Electrochromic device

ABSTRACT

An electrochromic element comprises an ion conduction layer between two conducting substrates, at least one of which is transparent. The ion conduction layer contains an organic compounds, which has both a structure exhibiting a cathodic electrochromic characteristic and a structure exhibiting an anodic electrochromic characteristic.

CROSS-REFERENCE OF RELATED APPLICATIONS

This Application is a continuation of co-pending U.S. patent applicationSer. No. 09/931,356, filed Aug. 16, 2001 now U.S. Pat. No. 6,519,072,which is a continuation of International Application No. PCT/JP00/00886,filed Feb. 17, 2000, the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

A method of forming a chromogenic layer for an electrochromic devicesuch as smart windows is known from Japanese Laid-Open PatentPublication No. 63-18336 disclosing a method in which a film ofchromogenic layer is formed by vacuum-evaporating an electrochromicactive substance such as tungsten oxide (WO₃) over a transparentelectrically conductive film.

However, this method requires techniques carried out under vacuumconditions, which lead to elevated production costs and the requirementsof a large-sized vacuum apparatus for the production of anelectrochromic device with a large-surface area. Furthermore, there is aproblem that the use of tungsten oxide results in an electrochromicdevice which can exhibit blue color only.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing, the object of the present invention is toprovide an electrochromic device which can be produced with inexpensivechromogenic materials by a simple method and can be changed in colortone.

The present invention relates to electrochromic devices which have anextensive use varied from transmission-type devices such as smartwindows, reflective-type devices such as antiglare mirrors forautomobiles, reflective-type devices such as decorative mirrors todisplays.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofpreferred embodiments of the invention, will be better understood whenread in conjunction with the appended drawings. For the purpose ofillustrating the invention, there is shown in the drawings embodimentswhich are presently preferred. It should be understood, however, thatthe invention is not limited to the precise arrangements andinstrumentalities shown.

In the drawings:

FIG. 1 is the NMR spectrum of a ferrocene-bipyridine derivative obtainedin Synthesis 1;

FIG. 2 is the NMR spectrum of a ferrocene-bipyridine derivative obtainedin Synthesis 2;

FIG. 3 is a cross-section of an electrochromic device of the presentinvention;

FIG. 4 is a cross-section of an electrochromic smart window of thepresent invention;

FIG. 5 is a cross-section of an electrochromic mirror of the presentinvention;

FIG. 6 is a plan view showing the non-displaying state of anelectrochromic panel of the present invention; and

FIG. 7 is a plan view showing the displaying state of an electrochromicpanel of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

After an extensive research and study, it was found that anelectrochromic device with the following structure can solve theabove-mentioned problems.

That is, an electrochromic device according to the present inventioncomprises an ion conductive layer arranged between a pair ofelectrically conductive substrates at least one of which is transparent,the ion conductive layer containing an organic compound (hereinafterreferred to as “electrochromic active compound (A)” or merely “Compound(A)”) having both a structure exhibiting a cathodic electrochromiccharacteristics and a structure exhibiting an anodic electrochromiccharacteristics.

In general, an electrochromic device necessarily contains a pair ofelectrically conductive substrates, at least one of which istransparent, an electrochromic active substance layer, and an ionconductive layer.

Two electrically conductive substrates are used in an electrochromicdevice according to the present invention similarly to the conventionalones. The term “electrically conductive substrate” refers to a substratefunctioning as an electrode. Therefore, the electrically conductivesubstrates used herein encompass those made from electrically conductivematerials and those obtained by laminating an electrically conductivelayer over one or both surfaces of a non-electrically conductivesubstrate. Regardless of whether the substrate is electricallyconductive or not, it has preferably a smooth surface at normaltemperatures. The surface, however, may be flat or curved and deformableunder stress as well.

At least one of the pair of electrically conductive substrates istransparent and the other may be transparent or opaque or may be areflective electrically conductive substrate which is capable ofreflecting light.

Generally, a device having electrically conductive substrates both ofwhich are transparent is suitable for displays and smart windows, whilea device having an electrically conductive transparent substrate and anopaque one is suitable for displays. A device having a transparentelectrically conductive substrate and a reflective one is suitable forelectrochromic mirrors.

The transparent electrically conductive substrate may be produced bylaminating a transparent electrode layer over a transparent substrate.The term “transparent” used herein denotes an optical transmissionranging from 10 to 100 percent.

No particular limitation is imposed on a material of the transparentsubstrate, which, therefore, may be color or colorless glasses,reinforced glasses or color or colorless transparent resins. Specificexamples of such resins are polyethylene terephtalate, polyethylenenaphthalate, polyamide, polysulfone, polyether sulfone, polyetheretherketone, polyphenylene sulfide, polycarbonate, polyimide, polymethylmethacrylate and polystyrene.

The transparent electrode layer may be made of a metal thin film ofgold, silver, chrome, copper and tungsten or an electrically conductivethin film of metal oxides. Specific examples of the metal oxides are ITO(In₂O₃—SnO₂), tin oxide, silver oxide, zinc oxide and vanadium oxide.The film thickness is usually within the range of 10 to 500 nm,preferably 50 to 300 nm. The surface resistance of the film is withinthe range of usually 0.5 to 500 Ω/sq, preferably 1 to 50 Ω/sq. Anysuitable method of forming a transparent electrode layer may be employeddepending on the type of metals and/or metal oxides forming theelectrode. The transparent electrode layer may be formed by vacuumevaporation, ion-plating, sputtering and sol-gel method.

For the purpose of imparting oxidation-reduction capability and electricdouble layer capacitance and improving electric conductivity, an opaqueelectrode activator may be partially applied to the surface of thetransparent electrode layer. The electrode activator may be a metal suchas copper, silver, gold, platinum, iron, tungsten, titanium and lithium,an organic material having oxidation-reduction capability, such aspolyaniline, polythiophen, polypyrrole and phthalocyanine, a carbonmaterial such as active carbon and graphite, a metal oxide such as V₂O₅,MnO₂, NiO and Ir₂O₃ and a mixture thereof.

Upon the formation of the electrode activator over a transparentelectrode layer, it is necessary not to harm the transparency thereofexcessively. Therefore, the opaque electrode activator may be appliedonto an electrode by forming thin stripes or dots of a compositioncomprising an active carbon fiber, graphite and an acrylic resin over atransparent ITO layer or forming mesh of a composition comprising V₂O₅,acetylene black and butyl rubber over a gold thin film.

The opaque electrically conductive substrate may be produced bysubstituting the transparent substrate of the above-describedtransparent electrically conductive substrate with an opaque substratesuch as various plastics, glasses, woods and stones if the substrateneed not be transparent.

Eligible reflective electrically conductive substrates for the presentinvention are (1) laminates obtained by laminating a reflectiveelectrode layer over a non-electrically conductive transparent or opaquesubstrate, (2) laminates obtained by laminating a transparent electrodelayer over one surface of a non-electrically conductive transparentsubstrate and a reflective layer over the other surface thereof, (3)laminates obtained by laminating a reflective layer over anon-electrically conductive transparent substrate and a transparentelectrode layer over the reflective layer, (4) laminates obtained bylaminating a transparent electrode layer over a reflective plate used asa substrate and (5) plate-like substrates which themselves havefunctions as a photo-reflective layer and an electrode layer.

The term “reflective electrode layer” denotes a thin film which has amirror surface and is electrochemically stable in performance as anelectrode. Specific examples of such a thin film are a metal film ofgold, platinum, tungsten, tantalum, rhenium, osmium, iridium, silver,nickel or palladium and an alloy film of platinum-palladium,platinum-rhodium or stainless. Any suitable method of forming such athin film may be employed such as vacuum evaporation, ion-plating andsputtering.

The substrate to be provided with a reflective electrode layer may betransparent or opaque. Therefore, the substrate may be theabove-described transparent substrate and various plastics, glasses,woods and stones which may not be transparent.

The term “reflective plate” or “reflective layer” denotes a substratehaving a mirror surface or a thin film which may be a plate of silver,chrome, aluminum, stainless, nickel-chrome or a thin film thereof.

If the above described reflective electrode layer per se is rigid, asubstrate may not be needed.

Regardless of whether an electrically conductive substrate istransparent or not, or reflective to light or not, a belt- or narrowstrip-like electrode may be arranged the peripheral of one or both ofthe two substrates.

An electrochromic device according to the present invention containsCompound (A) having in the molecules both a structure exhibitingcathodic electrochromic characteristics and a structure exhibitinganodic electrochromic characteristics, as an electrochromic activesubstance, Compound (A) being present in the ion conductive layer.

Therefore, when measuring the cyclic voltammetry of a cell provided withthe ion conductive layer in which Compound (A) is present, typicallysuch as an electrochemical measuring cell provided with an anode, acathode, and a reference electrode, it is observed that there arereduction peak and oxidation peak both derived from the structureexhibiting cathodic electrochromic characteristics and reduction peakand oxidation peak both derived from the structure exhibiting anodicelectrochromic characteristics. Furthermore, in the potential sweepregion, the increase and decrease of the optical density in the visiblerays region is reversibly observed. The measurement of cyclicvoltammetry is conducted by a conventional method, that is, by atriangular potential sweep in a constant potential method usingpotentiostate, and the sweep region is within the solvent and thepotential difference of the electrodes. Although no particularlimitation is imposed on the light source used for the measurement ofoptical density, a tungsten lump is usually used.

The number of structures exhibiting cathodic electrochromic propertiesand the number of structures exhibiting anodic electrochromicproperties, contained in Compound (A) are preferably 1 or 2 permolecule, respectively. Although not restricted, the lower limitconcentration of Compound (A) in the ion conductive layer of anelectrochromic device is usually 1 mM or more, preferably 5 mM or more,and more preferably 10 mM or more, and the upper limit concentration is100 mM or less, preferably 50 mM or less, and more preferably 40 mM orless.

Generally, the cathodic electrochromic properties of an electrochromicactive substance are derived from viologen structures (bipyridiniumion-pair structure) and anthraquinone structures, while the anodicelectrochromic properties are derived from pyrazoline, metallocene,phenylenediamine, benzidine, phenazine, phenoxadine, phenothiazine andtetrathiafulvalene structures.

Compound (A) used in the present invention has preferably a bipyridiniumion-pair structure represented by formula (1) given below as a structureexhibiting cathodic electrochromic characteristics and a metallocenestructure represented by formula (2) or (3) given below as a structureexhibiting anodic electrochromic characteristics:

wherein A- and B- are each independently a pair-anion selected from thegroup consisting of a halogen anion, ClO₄ ⁻, BF₄ ⁻, PF₆ ⁻, AsF₆ ⁻, SbF₆⁻, CHCOO⁻, and CH₃(C₆H₄)SO₃ ⁻; and

wherein R¹ and R² are each independently a hydrocarbon groups selectedfrom the group consisting of an alkyl, alkenyl and aryl group having 1to 10 carbon atoms, in the case where R¹ or R² is an aryl group, thearyl group may form a condensed ring together with a cyclopentadienylring, m is an integer of 0≦m≦4, n is an integer of 0≦n≦4, and Merepresents Cr, Co, Fe, Mg, Ni, Os, Ru, V, X—HF—Y, X—Mo—Y, X—Nb—Y,X—Ti—Y, X—V—Y or X—Zr—Y wherein X and Y are each independently selectedfrom the group consisting of hydrogen, halogen, and an alkyl grouphaving 1 to 12 carbon atoms.

In formulae (2) and (3), R¹ and R² are each independently a hydrocarbongroup selected from the group consisting of an alkyl, alkenyl and arylgroup having 1 to 10 carbon atoms. Examples of the alkyl group aremethyl, ethyl, i-propyl, n-propyl, n-butyl, t-butyl, n-pentyl, n-hexyl,and cyclohexyl groups. The aryl group is exemplified by phenyl group.Particularly preferred are methyl, ethyl, and propyl groups.

In the case where R¹ or R² is an aryl group, the aryl group may form acondensed ring by bonding to a cyclopentadienyl ring and R¹ or R² may bea group cross-linking two cyclopentadienyl rings in the metallocenestructure.

The letter “m” is an integer of 0≦m≦4, and the letter “n” is an integerof 0≦n≦4. Both m and n are preferably 0 or 1, and particularlypreferably 0.

Me represents Cr, Co, Fe, Mg, Ni, Os, Ru, V, X—HF—Y, X—Mo—Y, X—Nb—Y,X—Ti—Y, X—V—Y or X—Zr—Y and is preferably Fe. The X and Y referredherein are each independently hydrogen, halogen or an alkyl group having1 to 12 carbon atoms.

Compounds (A) preferred for the present invention aremetallocene-bipyridine derivatives represented by the following formulae(4) through (7):

wherein R¹, R², m, n, Me, A⁻ and B⁻ are the same as defined in formulae(1) through (3), R³ and R⁴ are each independently a hydrocarbon residuehaving 1 to 20, preferably 1 to 10 carbon atoms, and R⁵ is a hydrocarbongroup selected from the group consisting of an alkyl, cycloalkyl,alkenyl, aryl, or aralkyl group having 1 to 20, preferably 1 to 10carbon atoms, a heterocyclic group having 4 to 20, preferably 4 to 10carbon atoms, and a substituted hydrocarbon or heterocyclic groupobtained by substituting part of hydrogens of the hydrocarbon group orheterocyclic group with a substituent group.

Examples of the hydrocarbon residue for R³ and R⁴ are hydrocarbon groupssuch as alkylene groups and a various divalent groups having anester-bond unit, ether-bond unit, amide-bond unit, thioether-bond unit,amine-bond unit, urethane-bond unit, or silyl-bond unit in the part ofhydrocarbon groups. The divalent group having an ester-bond unit may beexemplified by those represented by the formula —R—COO—R— or —R—OCO—R—wherein R is an alkylene group having 1 to 8 carbon atoms. Specificexamples of the ester-bond unit are —C₄H₈—COO—C₂H₄, —C₄H₈—OCO—C₂H₄—,—C₄H₈—COO—C₄H₈—, and —C₄H₈—OCO—C₄H₈—. The divalent group having anether-bond unit may be exemplified by those represented by the formula—R—O—R wherein R is an alkylene group having 1 to 10 carbon atoms.Specific examples of the ether-bond unit are —C₄H₈—O—C₂H₄— and—C₄H₈—O—C₄H₈—. The divalent group having an amide-bond unit may beexemplified by those represented by the formula —R—CONH—R— or —R—NHCO—R—wherein R is an alkylene group having 1 to 8 carbon atoms. Specificexamples of the amide-bond unit are —C₄H₈—CONH—C₂H₄—, —C₄H₈—NHCO—C₂H₄—,—C₄H₈—CONH—C₄H₈—, and —C₄H₈—NHCO—C₄H₈—. The divalent group having athioether-bond unit may be those represented by the formula —R—S—R—wherein R is an alkylene group having 1 to 10 carbon atoms. Specificexamples of the thioether-bond unit are —C₄H₈—S—C₂H₄— and —C₄H₈—S—C₄H₈—.The divalent group having an amine-bond unit may be exemplified by thoserepresented by the formula —R—NH—R— wherein R is an alkylene grouphaving 1 to 10 carbon atoms and the formula —R—NH—Ph— wherein R is analkylene group having 1 to 10 carbon atoms and Ph is an arylene group ora substituted arylene group having 1 to 12 carbon atoms. Specificexamples of the amine-bond unit are —C₄H₈—NH—C₂H₄— and —C₄H₈—NH—C₄H₈—.The divalent group having a urethane-bond unit may be exemplified bythose represented by the formula —R—OCONH—R— or —R—NHCOO—R— wherein R isan alkylene group having 1 to 8 carbon atoms. Specific examples of theurethane-bond unit are —C₄H₈—OCONH—C₂H₄—, —C₄H₈—NHCOO—C₂H₄—,—C₄H₈—OCONH—C₄H₈—, and —C₄H₈—NHCOO—C₄H₈—. The divalent groups having asilyl-bond unit may be represented by those represented by the formula—R—Si(R′)₂—R— wherein R is an alkylene group having 1 to 8 carbon atomsand R′ is methyl or ethyl. Specific examples of the silyl-bond unit are—C₄H₈—Si(CH₃)₂—C₂H₄—, —C₄H₈—Si(CH₃)₂—C₄H₈—, —C₄H₈—Si(C₂H₅)₂—C₂H₄—, and—C₄H₈—Si(C₂H₅)₂—C₄H₈—.

Examples of the alkyl group for R⁵ are methyl, ethyl, i-propyl,n-propyl, n-butyl, t-butyl, n-pentyl, n-hexyl, and n-heptyl groups.Examples of the cycloalkyl is cyclohexyl group. Examples of the arylgroup are phenyl, tolyl, xylyl, and naphthyl. Examples of the alkenylgroup are vinyl and allyl groups. Examples of the aralkyl group arebenzyl and phenylpropyl groups. Examples of the heterocyclic aromaticgroup are 2-pyridyl, 4-pyridyl, 2-pyrimidyl, and isoquinoline groups.

In the case where R⁵ is a substituted hydrocarbon residue orheterocyclic group, examples of the substituent are alkoxy,alkoxycarbonyl, and acyl group having 1 to 10, preferably 1 to 5 carbonatoms, halogen, and cyano (—CN group), hydroxyl, nitro, and aminogroups. Examples of the alkoxy group are methoxy and ethoxy groups. Thealkoxycarbonyl group is exemplified by methoxycarbonyl. The acyl groupis exemplified by acetyl. The halogen is exemplified by Cl and F. Thesubstituted hydrocarbon residue is exemplified by methoxyphenyl,chlorophenyl, fluorophenyl, methoxychlorophenyl, cyanophenyl,acetylphenyl, methoxycarbonylphenyl, and methoxynaphtyl groups.

Preferred groups among the metallocene-bipyridine derivativesrepresented by formula (4) are ferrocene-bipyridine derivatives (a)represented by formula (8)

wherein R⁶ and R⁷ are each independently an alkylene group having 1 to20 carbon atoms, and A⁻ and B⁻ are the same as those defined in formula(1).

The alkylene group in formula (8) has preferably 1 to 10 carbon atomsand is preferably straight. Specific examples of the alkylene group aremethylene, ethylene, triethylene, tetramethylene, and pentamethylenegroups.

Specific examples of the ferrocene-bipyridine derivatives (a)represented by formula (8) are as follows:

The ferrocene-bipyridine derivatives (a) represented by formula (8) maybe synthesized in accordance with a conventional method as representedby the following reaction formula:

That is, 4,4′-bipyridine is firstly brought into the reaction with anexcess amount of ferrocene derivative having an elimination group suchas halogen or tosyl group at the terminal end of the alkyl group bondedto one of the cyclopentadienyl groups of ferrocene. The reaction iscarried out in a solvent such as dimethylformamide (DMF) anddimethylsulfoxide (DMSO) at a reaction temperature ranging from roomtemperature to reflux temperature, preferably from 30° C. to 150° C. for1 hour to 5 days, preferably 5 hours to 3 days, thereby producing anN,N′-bisferrocenylalkyl-4,4′-bipiridinium salt. In this case, theferrocene derivative is used in an amount of two or more, preferably 2to 10 equivalent mole of 4,4-bipyridine. The use of more ferrocene canshorten the reaction time. After the reaction, a poor solvent such asdiethylether or toluene is added to the reaction solution to beprecipitated, followed by filtration, thereby obtaining a desiredbipyridinium salt. The reaction product can be purified byrecrystallizing with water or methanol.

The anion-exchange of the bipyridinium salt thus obtained can beaccomplished by adding a saturated water solution of lithium salt orsodium salt to a water solution of the bipyridinium salt.

The ferrocene derivative used as the starting material in theabove-described synthesis, that is, a ferrocene derivative having anelimination group such as halogen or tosyl group at the terminal end ofthe alkyl group bonded to one of the cyclopentadienyl groups offerrocene may be prepared by the following methods.

The case where the carbon number of the alkyl group bonded to thecyclopentadienyl group is 1 or 2

The intended ferrocene derivative can be obtained by converting thehydroxyl groups of an alcohol compound which is obtained by reducing acommercially available ferrocene carboxylic acid with hydrogenatedlithium aluminum, in a conventional manner to halogen or tosyl.

The case where the carbon number of the alkyl group bonded to thecyclopentadienyl group is 3 or more

Ketocarboxylic acid is obtained by conducting the Friedel-Craftsreaction of ferrocene with anhydrous dicarboxylic acid in the presenceof an aluminum catalyst in a conventional manner. Next, theketocarboxylic acid is converted to an alcohol compound by reducing withhydrogenated lithium aluminum/aluminum chloride. In this case, it ispreferred to use an ether-based solvent such as ethers and THF. Thereaction temperature is within the range of preferably 0° C. to heatingreflux temperature. In the latter reaction, after the ketocarboxylicacid is reduced using 1 to 5 equivalent mole of hydrogenated lithiumaluminum, an alcohol compound having in its terminal ends hydroxylgroups can be obtained by adding aluminum chloride in the sameequivalent mole of the hydrogenated lithium aluminum. The alcoholcompound thus obtained is converted to halogen or tosyl in aconventional manner thereby obtaining the intended ferrocene derivative.

The metallocene-bipyridine derivative represented by the followingformula is one of those represented by formula (4) although it is notincorporated in the above-described metallocene-bipyridine derivative(a):

One preferred group of metallocene-bipyridine derivative among thoserepresented by formula (5) is ferrocene-bipyridinie derivatives (b)represented by formula (9); another preferred group isferrocene-bipyridine derivatives (c) represented by formula (10); andthe other preferred group is ferrocene-bipyridine derivatives (d)represented by formula (11):

wherein R⁸ is an alkylene group having 1 to 20 carbon atoms, R⁹ isselected from the group consisting of an alkyl or alkenyl having 1 to 10carbon atoms, an aryl group having 6 to 18 carbon atoms, a substitutedaryl group obtained by substituting part of the aryl group by an alkylor alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to8 carbon atoms, and an aralkyl group, and A⁻ and B⁻ are the same asthose defined in formula (1);

wherein R¹⁰ is an alkylene group having 1 to 20 carbon atoms, Ar¹ is anitrogen-containing heterocyclic group selected from the groupconsisting of pyridine, pyrimidine and isoquinolyl groups or such aheterocyclic group part of which is substituted by an alkyl and/oralkoxy group having 1 to 5 carbon atoms, and A⁻ and B⁻ are the same asthose defined in formula (1); and

wherein R¹¹ is an alkylene group having 1 to 20 carbon atoms, R¹² isselected from the group consisting of alkyl, alkenyl, aryl, and aralkylgroups having 1 to 20 carbon atoms, Ar² is a divalent aromatichydrocarbon group having 6 to 20 carbon atoms, A⁻ and B⁻ are the same asthose defined in formula (1).

In formula (11), the alkylene group for R¹¹ has preferably 1 to 10carbon atoms and is particularly preferably methylene, trimethylene,tetramethylene, and pentamethylene groups.

When R¹² is an alkyl group, it has preferably 1 to 10 carbon atoms.Specific examples are methyl, ethyl, propyl, pentyl, heptyl, and octylgroups.

When R¹² is an alkenyl group, the carbon number thereof is 2 to 20,preferably 2 to 10. Specific examples are allyl and vinyl groups.

When R¹² is an aryl group, the carbon number thereof is 6 to 20,preferably 6 to 12. Specific examples are phenyl and tolyl groups.

When R¹² is an aralkyl group, the carbon number thereof is 7 to 20,preferably 7 to 12. Specific examples are benzyl, phenethyl, andphenylpropyl groups.

In formula (12), Ar² is a divalent aromatic hydrocarbon group and thecarbon number thereof is 6 to 20, preferably 6 to 12. Specific examplesof the divalent aromatic hydrocarbon group are arylene groups such asphenylene, biphenylene, and naphthylene groups. The aromatic hydrocarbongroups may have a substituent. Examples of the substituent are an alkylor alkenyl group having 1 to 15, preferably 1 to 6 carbon atoms, an arylhaving 6 to 12, preferably 6 to 8 carbon atoms, a cyano group, a nitrogroup, a hydroxyl group, an alkoxy group having 1 to 15, preferably 1 to6 carbon atoms, and an amino group. Preferred are alkyl groups.

Specific examples of the ferrocene-bipyridine derivatives (b)represented by formula (9) are as follows:

The ferrocene-bipyridine derivatives (a) represented by formula (8) maybe synthesized in accordance with a conventional method as representedby the following reaction formula:

That is, 4,4′-bipyridine is firstly brought into the reaction with anexcess amount of ferrocene derivative having an elimination group suchas halogen or tosyl group at the terminal end of the alkyl group bondedto one of the cyclopentadienyl groups of ferrocene. The reaction iscarried out in a solvent such as dimethylformamide (DMF) anddimethylsulfoxide (DMSO) at a reaction temperature ranging from roomtemperature to reflux temperature, preferably from 30° C. to 150° C. for1 hour to 5 days, preferably 5 hours to 3 days, thereby producing anN,N′-bisferrocenylalkyl-4,4′-bipiridinium salt. In this case, theferrocene derivative is used in an amount of two or more, preferably 2to 10 equivalent mole of 4,4-bipyridine. The use of more ferrocene canshorten the reaction time. After the reaction, a poor solvent such asdiethylether or toluene is added to the reaction solution to beprecipitated, followed by filtration, thereby obtaining a desiredbipyridinium salt. The reaction product can be purified byrecrystallizing with water or methanol.

The anion-exchange of the bipyridinium salt thus obtained can beaccomplished by adding a saturated water solution of lithium salt orsodium salt to a water solution of the bipyridinium salt.

The ferrocene derivative used as the starting material in theabove-described synthesis, that is, a ferrocene derivative having anelimination group such as halogen or tosyl group at the terminal end ofthe alkyl group bonded to one of the cyclopentadienyl groups offerrocene may be prepared by the following methods.

The Case Where the Carbon Number of the Alkyl Group Bonded to theCyclopentadienyl Group is 1 or 2

The intended ferrocene derivative can be obtained by converting thehydroxyl groups of an alcohol compound which is obtained by reducing acommercially available ferrocene carboxylic acid with hydrogenatedlithium aluminum, in a conventional manner to halogen or tosyl.

The Case Where the Carbon Number of the Alkyl Group Bonded to theCyclopentadienyl Group Is 3 or More

Ketocarboxylic acid is obtained by conducting the Friedel-Craftsreaction of ferrocene with anhydrous dicarboxylic acid in the presenceof an aluminum catalyst in a conventional manner. Next, theketocarboxylic acid is converted to an alcohol compound by reducing withhydrogenated lithium aluminum/aluminum chloride. In this case, it ispreferred to use an ether-based solvent such as ethers and THF. Thereaction temperature is within the range of preferably 0° C. to heatingreflux temperature. In the latter reaction, after the ketocarboxylicacid is reduced using 1 to 5 equivalent mole of hydrogenated lithiumaluminum, an alcohol compound having in its terminal ends hydroxylgroups can be obtained by adding aluminum chloride in the sameequivalent mole of the hydrogenated lithium aluminum. The alcoholcompound thus obtained is converted to halogen or tosyl in aconventional manner thereby obtaining the intended ferrocene derivative.

The metallocene-bipyridine derivative represented by the followingformula is one of those represented by formula (4) although it is notincorporated in the above-described metallocene-bipyridine derivative(a):

One preferred group of metallocene-bipyridine derivative among thoserepresented by formula (5) is ferrocene-bipyridine derivatives (b)represented by formula (9); another preferred group isferrocene-bipyridine derivatives (c)

represented by formula (10); and the other preferred group isferrocene-bipyridine derivatives (d) represented by formula (11):

wherein R⁸ is an alkylene group having 1 to 20 carbon atoms, R⁹ isselected from the group consisting of an alkyl or alkenyl having 1 to 10carbon atoms, an aryl group having 6 to 18 carbon atoms, a substitutedaryl group obtained by substituting part of the aryl group by an alkylor alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to8 carbon atoms, and an aralkyl group, and A⁻ and B⁻ are the same asthose defined in formula (1);

wherein R¹⁰ is an alkylene group having 1 to 20 carbon atoms, Ar¹ is anitrogen-containing heterocyclic group selected from the groupconsisting of pyridine, pyrimidine and isoquinolyl groups or such aheterocyclic group part of which is substituted by an alkyl and/oralkoxy group having 1 to 5 carbon atoms, and A⁻ and B⁻ are the same asthose defined in formula (1); and

wherein R¹¹ is an alkylene group having 1 to 20 carbon atoms, R¹² isselected from the group consisting of alkyl, alkenyl, aryl, and aralkylgroups having 1 to 20 carbon atoms, Ar² is a divalent aromatichydrocarbon group having 6 to 20 carbon atoms, A⁻ and B⁻ are the same asthose defined in formula (1).

In formula (11), the alkylene group for R¹¹ has preferably 1 to 10carbon atoms and is particularly preferably methylene, trimethylene,tetramethylene, and pentamethylene groups.

When R¹² is an alkyl group, it has preferably 1 to 10 carbon atoms.Specific examples are methyl, ethyl, propyl, pentyl, heptyl, and octylgroups.

When R¹² is an alkenyl group, the carbon number thereof is 2 to 20,preferably 2 to 10. Specific examples are allyl and vinyl groups.

When R¹² is an aryl group, the carbon number thereof is 6 to 20,preferably 6 to 12. Specific examples are phenyl and tolyl groups.

When R¹² is an aralkyl group, the carbon number thereof is 7 to 20,preferably 7 to 12. Specific examples are benzyl, phenethyl, andphenylpropyl groups.

In formula (12), Ar² is a divalent aromatic hydrocarbon group and thecarbon number thereof is 6 to 20, preferably 6 to 12. Specific examplesof the divalent aromatic hydrocarbon group are arylene groups such asphenylene, biphenylene, and naphthylene groups. The aromatic hydrocarbongroups may have a substituent. Examples of the substituent are an alkylor alkenyl group having 1 to 15, preferably 1 to 6 carbon atoms, an arylhaving 6 to 12, preferably 6 to 8 carbon atoms, a cyano group, a nitrogroup, a hydroxyl group, an alkoxy group having 1 to 15, preferably 1 to6 carbon atoms, and an amino group. Preferred are alkyl groups.

Specific examples of the ferrocene-bipyridine derivatives (b)represented by formula (9) are as follows:

Specific examples of the ferrocene-bipyridine derivatives (c)represented by formula (10) are as follows:

The followings are specific examples of the ferrocene-bipyridinederivatives (d) represented by formula (11).

Although not incorporated in the above-mentioned metallocene-bipyridine

derivatives (b) to (d), the following are also examples of thoserepresented by formula (5):

The derivatives (b) to (d) of formulae (9) to (11) may be synthesized inaccordance with a conventional method as described below.

Production of the ferrocene-bipyridine Derivative (b)

(1) the case where R⁹ is an alkyl, alkenyl, or aralkyl group

As shown in the above reaction formulae, 4,4′-bipyridine is firstlybrought into the reaction with an excess amount of ferrocene derivativehaving an elimination group such as halogen or tosyl at the terminal endof the alkyl group bonded to one of the cyclopentadienyl groups offerrocene (see reaction 1 above). The reaction is carried out in asolvent such as toluene, diethylether, and acetone at a reactiontemperature of 0° C. to 150° C., preferably room temperature to 100° C.4,4′-bipyridine is preferably used in an excess amount with respect tothe ferrocene derivative. More specifically, 4,4′-bipyridine is used inan amount of 1 to 50, preferably 1.5 to 20 equivalent mole of theferrocene derivative such that they are reacted at a ratio of 1:1. The4,4-pyridinium salt, i.e., the reaction product precipitates in thereaction solvent. The precipitate can be recovered by filtration.

Next, the 4,4-pyridinium salt is brought into the reaction with alkanehaving an elimination group such as a halogenated alkyl group and atosyl group so as to obtain a 4-bipyridinium salt (see reaction 2above). A reaction solvent such as dimethyl formaldehyde (DMF) anddimethylsulfoxide (DMSO) is used in this reaction. The reactiontemperature is within the range of 0° C. to 100° C., preferably roomtemperature to 80° C. It is preferred to use an excess halogenated alkylwith respect to the pyridinium salt with the objective of theenhancement of the reaction speed. Specifically, a halogenated alkyl isused in an amount of 1 to 100 preferably 1.5 to 20 equivalent mole ofthe pyridinium salt.

When a pyridinium salt is converted to a bipyridinium salt, an alkylgroup is introduced into the reaction system using a halogenated alkyl.If an alkenyl or aralkyl group is desirously introduced, it can be doneby conducting the reaction using a halogenated alkenyl or aralkyl underthe same conditions where an alkyl group is introduced.

After the reaction, a poor solvent such as diethylether or toluene isadded to the reaction solution to be precipitated, followed byfiltration, thereby obtaining a desired bipyridinium salt. The reactionproduct can be purified by recrystallizing with water or methanol.

The pair-anion exchange of the bipyridinium salt thus obtained can beeasily accomplished by recrystallization using a saturated watersolution of an anion corresponding to A⁻ and B⁻ in formula (1) such aslithium salt, sodium salt, and ammonium salt.

(2) the case where R⁹ is an aryl group or a substituted aryl group

As shown in the above reaction formulae, 4,4-bipyridine anddinitrochlorobenzene are reacted at a molar ratio of 1:1. Alcohols,tetrahydrofuran (THF), and DMF may be used as a reaction solvent.Dinitrochlorobenzene is introduced into 4,4′-bipyridine by conductingthe reaction at a temperature of usually 50° C. to reflux temperaturefor 2 hours to 48 hours (see reaction 1 above).

Next, the intended aryl group (Ar) can be introduced by conducting areaction using one or more equivalent mole of anilines and a solventsuch as water and alcohols at reflux temperature for 24 hours to 48hours (see reaction 2).

After this procedures, the bipyridine derivative obtained in reaction 2is brought into a reaction with a ferrocene derivative having anelimination group such as halogen or tosyl group at the terminal end ofthe alkyl group bonded to one of the cyclopentadienyl groups offerrocene. The ferrocene derivative is preferably used in an excessamount. The reaction temperature is within the range of room temperatureto 150° C., preferably 40° C. to 100° C. Specifically, the reaction isconducted using the ferrocene derivative in an amount of 1 to 20,preferably 1.1 to 5 equivalent mole of the bipyridine derivative for 10hours to 7 days thereby introducing the ferrocene derivative into thebipyridine derivative (see reaction 3 above).

After the reaction, a poor solvent such as diethylether and toluene isadded to the reaction solution to be precipitated, followed byfiltration, thereby obtaining the intended product. The reaction productcan be purified by recrystallizing with water or methanol.

The pair-anion exchange can be accomplished by adding a water-, DMF- orDMSO-solution of the bipyridinium salt into a saturated water solutionof an excess lithium salt, sodium salt or ammonium salt at roomtemperature. The intended product can be obtained by filtrating andrecover the precipitate. The purification can be done byrecrystallization using water or methanol.

Production of Ferrocene-bipyridine Derivative (c)

As shown in the above reaction formulae, 4,4′-bipyridine and anitrogen-containing heterocyclic aromatic compound (Hc) such aschloropyridin and chloropyrimidine are reacted at a molar ratio of 1:1.In this case, alcohols, THF or DMF may be used as a reaction solvent.The reaction is usually conducted at a temperature of 50° C. to refluxtemperature for 2 hours to 48 hours thereby introducing anitrogen-containing heterocyclic group as a substituent into the4,4′-bipyridine (see reaction 1).

Next, the bipyridine derivative thus obtained is brought into thereaction with a ferrocene derivative having an elimination group such ashalogen and tosyl at the terminal ends of the alkyl group, in a solutionof alcohol, THF or DMF thereby introducing the ferrocene derivative intothe bipyridine derivative (see reaction 2 above). The reactiontemperature is within the range of room temperature to 150° C.,preferably 40° C. to 100° C. In reaction 2, a ferrocene derivative ispreferably used in an excess amount with respect to a 4,4-bipyridinederivative. Specifically, a ferrocene derivative can be introduced forthe reaction time of 10 hours to 7 days using a ferrocene derivative inan amount of 1 to 20, preferably 1.1 to 5 equivalent mole of a4,4-bipyridine derivative.

After the reaction, a poor solvent such as diethylether and toluene isadded to the reaction solution, followed by filtration of theprecipitate, thereby obtaining the intended product. The reactionproduct can be purified by recrystallizing with water or methanol.

The pair-anion exchange can be accomplished by adding a water-, DMF- orDMSO-solution solution of the bipyridinium salt into a saturated watersolution of an excess lithium salt, sodium salt or ammonium salt at roomtemperature. The intended product can be obtained by filtrating andrecovering the precipitate. The purification can be done byrecrystallization using water or methanol.

In the above-described example of producing a ferrocene-bipyridinederivative (c), the order of reaction 1 and reaction 2 may be reversed.In such a case, the reaction is preferably conducted under an atmosphereof nitrogen at a temperature of room temperature to 60° C. so as tosuppress the oxidation of the ferrocene portion.

Production of Ferrocene-bipyridine Derivative (d)

As shown in the above reaction formulae, a nitrogen-substituted4,4′-bipyridine salt and dinitrochlorobenzene are reacted so as tointroduce dinitrophenyl (see reaction 1 above). Generally, althoughthese compounds are reacted at a molar ratio of 1:1, an excessdinitrochlorobenzene is preferably used so as to expedite the reaction.Alcohols, THF or DMF is used as a reaction solvent. The reaction isconducted at a temperature of 50° C. to reflux temperature for 2 hoursto 48 hours.

In reaction 2, an aniline derivative, i.e., an aromatic compound havingtwo primary amino group, such as phenylenediamine, benzidine, andnaphthalenediamine is used in an amount of one or more equivalent moleof a bipyridine derivative in and hear-refluxed in a water solution for10 to 72 hours, thereby introducing an aromatic substituent having anamino group into the bipyridine derivative.

After the reaction, the water is removed by vacuum-concentration. Theconcentrates thus obtained were dissolved in an alcohol andreprecipitated in ether thereby obtaining the intended product.

A ferrocene derivative is introduced by reacting a ferrocene derivativehaving an elimination group such as halogen and tosyl at the terminalends of the alkyl group with the product obtained in reaction 2 in asolution of water, alcohol, THF or DMF (see reaction 3). In thisreaction, NaOH₃, NaHCO₃, NaOH, or KCO₃ may be used. The reaction isconducted at a temperature of room temperature to 150° C., preferably40° C. to 100° C. The charging ratio of the ferrocene derivative to the4,4′-bipyridine derivative is preferably 1:1. The introduction of aferrocene derivative is completed after one hour to 4 day.

After the reaction and if water is used, it is removed by vacuumconcentration, followed by dissolving the methanol and DMF and addingdiethylether or toluene as a poor solvent. The precipitate is filtratedthereby obtaining the intended product. The product can be purified byrecrystallizing with water or methanol.

The pair-anion exchange can be accomplished by adding a water-, DMF- orDMSO-solution of a bipyridinium salt into a saturated water solution ofan excess lithium salt, sodium salt or ammonium salt at roomtemperature. The intended product can be obtained by filtrating andrecovering the precipitate. The purification can be done byrecrystallization using water or methanol.

In the above-described production method of ferrocene derivatives (b) to(d), there is omitted an explanation as to the preparation method of aferrocene derivative used as one of the starting materials, i.e., aferrocene derivative having a halogen or an elimination group such astosyl group at the terminal end of the alkyl group bonded to one of thecyclopentadienyl group because such an explanation is made with respectto the derivative (a).

Specific examples of ferrocene-bipyridine derivative represented byformula (6) or (4) are as follows:

Next, an ion conductive layer containing Compound (A) of the presentinvention will be described.

Generally, the ion conductive layer in an electrochromic device has anion conductivity of 1×10⁻⁷ S/cm and a function to color, decolor, anddiscolor the above-described electrochromic active substance. Such anion conductive layer may be formed using either a liquid-, gelatinizedliquid- or solid-type ion conductive substance. Solid-type ionconductive substances is preferably used such that it is possible toproduce a solid-type electrochromic device for practical use.

Liquid-type Ion Conductive Substance

A liquid-type ion conductive substance is prepared by dissolving asupporting electrolyte such as salts, acids, and alkalis in a solvent.

Eligible solvents are any type of those generally used inelectrochemical cells and batteries. Specific examples of such solventsare water, acetic anhydride, methanol, ethanol, tetrahydrofuran,propylene carbonate, nitromethane, acetonitrile, dimethylformamide,dimethylsulfoxide, hexamethylphosamide, ethylene carbonate,dimethoxyethane, γ-butyrolactone, γ-valerolactone, sulforan,dimethoxyethane, propionnitrile, glutaronitrile, adiponitrile,methoxyacetonitrile, dimethylacetoamide, methylpyrrolidinone,dimethylsulfoxide, dioxolane, trimethylphosphate and polyethyleneglycol. Preferred are propylene carbonate, ethylene carbonate,dimethylsulfoxide, dimethoxyethane, acetonitrile, γ-butyrolactone,sulforan, dioxolane, dimethylformamide, dimethoxyethane,tetrahydrofuran, adiponitrile, methoxyacetonitrile, dimethylacetoamide,methylpyrrolidinone, dimethylsulfoxide, dioxolane, trimethylphosphate,and polyethylene glycol. The solvent may be used singlely or incombination.

Although not restricted, the solvent is used in an amount of 20 percentby weight or greater, preferably 50 percent by weight or greater, andmore preferably 70 percent by weight of the ion conductive layer. Theupper limit is 98 percent by weight, preferably 95 percent by weight,and more preferably 90 percent by weight.

Eligible supporting electrolytes are salts, acids, and alkalis which aregenerally used in the filed of electrochemistry or batteries.

Salts may be inorganic ion salts such as alkali metal salts and alkalineearth metal salts, quaternary ammonium salts, cyclic quaternary ammoniumsalts, and quaternary phosphonium salts.

Specific examples of such salts are alkali metal salts, such as LiCIO₄,LiSCN, LiBF₄, LiAsF₆, LiCF₃SO₃, LiPF₆, LiI, NaI, NaSCN, NaClO₄, NaBF₄,NaAsF₆, KSCN and KCl, quaternary ammonium salts such as (CH₃)₄NBF₄,(C₂H₅)₄NBF₄, (n-C₄H₉)₄NBF₄, (C₂H₅)₄NBR, (C₂H₅)₄NCIO₄ and (n-C₄H₉)₄NCIO₄,(C₂H₅)₃CH₃NBF₄, (C₂H₅)₃CH₃NClO₄, (C₂H₅)₂(CH₃)₂NBF₄, (C₂H₅)₂(CH₃)ClO₄,(C₂H₅)(CH₃)₃BF₄, (C₂H₅)(CH₃)₃ClO₄, and those represented by thefollowing formulae:

and phosphonium salts such as (CH₃)₄PBF₄, (C₂H₅)₄PBF₄, (C₃H₇)₄PBF₄, and(C₄H₉)₄PBF₄, mixtures thereof.

No particular limitation is imposed on acids. Eligible acids areinorganic acids and organic acids, and more specifically sulfuric acid,hydrochloric acid, phosphoric acids, sulfonic acids, and carboxylicacid.

No particular limitation is imposed on alkalis. Eligible alkalis aresodium hydroxide, potassium hydroxide, and lithium hydroxide.

The amount of the supporting electrolyte inclusive of the case of unusedin the ion conductive layer is arbitrary selected. Generally, thesupporting electrolyte is present in the ion conductive layer in theupper limit amount of 20 M or less, preferably 10 M or less, and morepreferably 5 M or less and in the lower limit amount of 0.01 M orgreater, preferably 0.05 M or greater, and more preferably 0.1 M orgreater.

Gelatinized Liquid Ion Conductive Substance

The term “gelatinized liquid ion conductive substance” designates asubstance obtained by thickening or gelatinizing the above-describedliquid-type ion conductive substance. The gelatinized liquid ionconductive substance is prepared by blending a polymer or a gelatinizerwith a liquid-type ion conductive substance.

No particular limitation is imposed on the polymer. Eligible polymersare polyacrylonitrile, carboxymethyl cellulose, poly vinyl chloride,polyethylene oxide, polyurethane, polyacrylate, polymethacrylate,polyamide, polyacrylicamide, cellulose, polyester, polypropylene oxideand nafion.

No particular limitation is imposed on the gelatinizer. Eligiblegelatinizers are oxyethylene methacrylate, oxyethylene acrylate,urethaneacrylate, acrylicamide and agar—agar.

Solid-type Ion Conductive Substance

The term “solid-type ion conductive substance” designates a substancewhich is solid at room temperature and has an ion conductivity. Suchsubstances are exemplified by polyethyleneoxide, a polymer ofoxyethylenemethacrylate, nafion, polystylene sulfonate, Li₃N, Na-β-Al₂O₃and Sn(HPO₄)₂.H₂O. Other than these, there may be used a polymeric solidelectrolyte obtained by dispersing a supporting electrolyte in apolymeric compound obtained by polymerizing anoxyalkylene(metha)acrylate-based compound or a urethane acrylate-basedcompound.

First examples of the polymer solid electrolytes recommended by thepresent invention are those obtained by solidifying a compositioncontaining the above-described organic polar solvent and supportingelectrolyte used arbitrary and a urethaneacrylate represented by formula(12) below.

The term “cure” used herein designates a state where the polymerizablemonomer in the mixture is cured with the progress of polymerization orcrosslinking and thus the entire mixture does not flow at roomtemperature. The composition thus cured often has the basic structure inthe form of network (three-dimensional network structure).

Formula (12) is represented by

wherein R¹⁴ and R¹⁵ are each independently a group selected from thoserepresented by formulae (13), (14) and (15), R¹⁶ and R¹⁷ are eachindependently a divalent hydrocarbon group having 1 to 20, preferably 2to 12 carbon atoms, Y is a polyether unit, a polyester unit, apolycarbonate unit or a mixed unit thereof, a is an integer of 1 to 100,preferably 1 to 50, more preferably 1 to 20:

formulae (13), (14) and (15) being represented by

In formulae (13), (14) and (15), R¹⁸, R¹⁹ and R²⁰ are each independentlyhydrogen or an alkyl group having 1 to 3 carbon atoms and R²¹ is adivalent to quatervalent organic residue having 1 to 20, preferably 2 to8 carbon atoms. Specific examples of the organic residue are hydrocarbonresidues such as alkyltolyl groups, alkyltetratolyl groups and alkylenegroups represented by the formula

wherein R²² is an alkyl group having 1 to 3 alkyl group or hydrogen, bis an integer of 0 to 6 and if b is 2 or greater, the groups of R²² maybe the same or different.

The hydrogen atom in formula (16) may be partially substituted by anoxygen-containing hydrocarbon group such as an alkoxy group having 1 to6, preferably 1 to 3 carbon atoms and an aryloxy group having 6 to 12carbon atoms.

Specific examples of the organic residue of R²¹ are methylene,tetramethylene, 1-methyl-ethylene, 1,2,3-propanetoriyl, andneopentanetoriyl.

The divalent hydrocarbon group for R¹⁶ and R¹⁷ in formula (12) may beexemplified by aliphatic hydrocarbon groups, aromatic hydrocarbon groupsand alicyclic hydrocarbon groups. The aliphatic hydrocarbon group may bean alkylene group represented by formula (16) above.

The divalent aromatic and alicyclic hydrocarbon groups may beexemplified by hydrocarbon groups represented by the following formulae(17), (18) and (19):

In formulae (17) through (19), R²³ and R²⁴ are each independently aphenylene group, a substituted phenylene group (an alkyl-substitutedphenylene group), a cycloalkylene group and a substituted cycloalkylenegroup (an alkyl-substituted cycloalkylene group), and R²⁵, R²⁶, R²⁷ andR²⁸ are each independently hydrogen or an alkyl group having 1 to 3carbon atoms and c is an integer of 1 to 5.

Specific examples of R¹⁶ and R¹⁷ in formula (12) are the followingdivalent groups:

In formula (12), Y indicates a polyether unit, a polyester unit, apolycarbonate unit or mixed units thereof. Each of these units isrepresented by the following formulae:

In formulae (a) through (d), R²⁹, R³⁰, R³¹, R³², R³³ and R³⁴ are eachindependently a divalent hydrocarbon group residue having 1 to 20,preferably 2 to 12 carbon atoms. The hydrocarbon residue is preferably astraight-chain or branched alkylene group. More specifically, R³¹ ispreferably methylene, ethylene, trimethylene, tetramethylene,pentamethylene, hexamethylene, and propylene groups. Specific examplesof R²⁹, R³⁰, R³², R³³ and R³⁴ are ethylene and propylene groups. c′ isan integer of 2 to 300, preferably 10 to 200. d′ is an integer of 1 to300, preferably 2 to 200. e′ is an integer of 1 to 200, preferably 2 to100. e′ is an integer of of 1 tp 200, preferably 2 to 200. f′ is aninteger of 1 to 300, preferably 10 to 200.

In formulae (a) through (d), each of the units may be the same ordifferent. In other words, if there exists a plurality of the groups ofeach R²⁹ through R³⁴, the groups of each R²⁹ through R³⁴ may be the sameor different.

The polyurethane monomer of formula (12) has a molecular-averagemolecular weight in the range of 2,500 to 30,000, preferably 3,000 to20,000 and has preferably 2 to 6, more preferably 2 to 4 functionalgroups per molecule. The polyurethane monomer of formula (12) may beprepared by any suitable conventional method.

A polymeric solid electrolyte containing an urethaneacrylate of formula(12) is prepared by admixing a urethaneacrylate, a solvent and asupporting electrolyte both described with respect to the liquid typeion conductive substance so as to obtain a precursor composition andsolidifying the composition. The amount of the solvent is selected fromthe range of 100 to 1,200 parts by weight, preferably 200 to 900 partsby weight per 100 parts by weight of the urethaneacrylate. A too lessamount of the solvent would result in insufficient ion conductivity,while a too much amount of the solvent would cause reduced mechanicalstrength. No particular limitation is imposed on the supportingelectrolyte and it may not be added. The upper limit is usually 30percent by weight or less, preferably 20 percent by weight of the amountof the solvent, while the lower limit is 0.1 percent by weight or more,preferably 1 percent by weight or more.

If necessary, cross-linkers or polymerization initiators may be added tothe polymeric solid electrolyte containing the urethaneacrylate.

Second examples of the polymeric solid substance recommended by thepresent invention are those obtained by solidifying a compositioncomprising a solvent, a supporting electrolyte which may not be added,an acryloyl- or methacrylate-modified polyalkylene oxide (bothhereinafter referred to as “modified polyalkylene oxide”.

The modified polyalkylene oxide encompasses monofunctional-,bifunctional- and polyfunctional-modified polyalkylene oxides. Thesemodified polyalkylene oxides may be used individually or in combination.It is preferred to use a monofunctional modified polyalkylene oxide asan essential component in combination with bifunctional and/orpolyfunctional ones. It is particularly preferred to use amonofunctional modified polyalkylene oxide mixed with a bifunctionalone. The mix ratio is arbitrary selected. Bifunctional- and/orpolyfunctional-modified polyalkylene oxides are used in a total amountof 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight of100 parts by weight of a monofunctional polyalkylene oxide.

A monofunctional modified polyalkylen oxide is represented by theformula

wherein R³⁵, R³⁶, R³⁷ and R³⁸ are each hydrogen and an alkyl grouphaving from 1 to 5 carbon atoms and g′ is an integer of 1 or more.

In formula (20), examples of the alkyl group of R³⁵, R³⁶, R³⁷ and R³⁸which may be the same or different include methyl, ethyl, i-propyl,n-propyl, n-butyl, t-butyl and n-pentyl. Preferred for R³⁵, R³⁶ and R³⁷are hydrogen and a methyl group. Preferred for R³⁸ are hydrogen andmethyl and ethyl groups.

In formula (20), g′ is an integer of 1 or more and within the range ofusually 1≦g′≦100, preferably 2≦g′≦50, more preferably 2≦g′<30.

Specific examples of the compound of formula (20) are those having 1 to100, preferably 2 to 50, more preferably 2 to 20 oxyalkylen units, suchas methoxypolyethylene glcyol methacrylate, methoxypolypropylene glycolmethacrylate, ethoxypolyethylene glycol methacrylate,ethoxypolypropylene glycol methacrylate,methoxypolyethylene glycolacrylate, methoxypolypropylene glycol acrylate, ethoxypolyethyleneglycol acrylate, ethoxypolypropylene glycol acrylate and mixturesthereof. Among these, preferred are methoxypolyethylene glcyolmethacrylate and methoxypolyethylene glycol acrylate.

If g′ is 2 or greater, the monofunctional modified polyalkylene oxidemay be those having different oxyalkylene units, that is, copolymerizedoxyalkylene units which may be alternating-, block- orrandom-polymerized and have 1 to 50, preferably 1 to 20 oxyethyleneunits and 1 to 50, preferably 1 to 20 oxypropylene units. Specificexamples of such copolymers are methoxypoly(ethylene.propylene)glycolmethacrylate, ethoxypoly(ethylene.propylene)glycol methacrylate,methoxypoly(ethylene.propylene)glycol acrylate,ethoxypoly(ethylene.propylene)glycol acrylate and mixtures thereof.

The difunctional modified polyalkylene oxide is represented by theformula

wherein R³⁹, R⁴⁰, R⁴¹ and R⁴² are each independently hydrogen or analkyl group having 1 to 5 carbon atoms and h′ is an integer of 1 ormore.

The polyfunctional modified polyalkylene oxide having 3 or morefunctional groups is represented by the formula

wherein R⁴³, R⁴⁴ and R⁴⁵ are each independently hydrogen or an alkylgroup having 1 to 5 carbon atoms, i′ is an integer of greater than 1, j′is an integer of 2 to 4 and L is a connecting groups of valencerepresented by “j′”.

In formula (21), R³⁹, R⁴⁰, R⁴¹ and R⁴² are each independently hydrogenor an alkyl group having 1 to 5 carbon atoms. Specific examples of thealkyl group are methyl, ethyl, i-propyl, n-propyl, n-butyl, t-butyl andn-pentyl groups. It is preferred that R³⁹ is hydrogen or methyl group,R⁴⁰ is hydrogen or methyl group, R⁴¹ is hydrogen or methyl group and R⁴²is hydrogen, methyl or ethyl group.

The letter “h′” in formula (21) is an integer of greater than 1 andwithin the range of usually 1≦h′≦100, preferably 2≦h′≦50, morepreferably 2≦h′≦30. Specific examples of such compounds are those having1 to 100, preferably 2 to 50, more preferably 2 to 20 of oxyalkyleneunits, such as polyethylene glycol dimethacrylate, polypropylene glycoldimethacrylate, polyethylene glycol methacrylate, polypropylene glycoldimethacrylate, and mixtures thereof.

If h′ is 2 or greater, the difunctional modified polyalkylene oxide maybe those having different oxyalkylene units, that is, copolymerizedoxyalkylene units which may be alternating-, block- orrandom-polymerized and have 1 to 50, preferably 1 to 20 oxyethyleneunits and 1 to 50, preferably 1 to 20 oxypropylene units. Specificexamples of such copolymers are poly(ethylene.propylene)glycoldimethacrylate, poly(ethylene.propylene)glycol diacrylate and mixturesthereof.

R⁴³, R⁴⁴ and R⁴⁵ in formula (22) are each independently hydrogen or analkyl group having 1 to 5 carbon atoms. Specific examples of the alkylgroup are methyl, ethyl, i-propyl, n-propyl, n-butyl, t-butyl andn-pentyl groups. R⁴³, R⁴⁴ and R⁴⁵ are each preferably hydrogen or methylgroup.

In formula (22), i′ is an integer of 1 or greater and within the rangeof usually 1≦i′≦100, preferably 2≦i′≦50, more preferably 2≦i′≦30.

The letter “j′” denotes a number of connecting group “L” and is aninteger of 2≦j′≦4.

Connecting group “L” is a divalent, trivalent or quatravalenthydrocarbon group having 1 to 30, preferably 1 to 20 carbon atoms. Thedivalent hydrocarbon group may be alkylene, arylene, arylalkylene andalkylarylene groups and hydrocarbon groups having those groups as a baseskeleton. Specific examples of the divalent hydrocarbon group are amethylene group, an ethylene group and a group represented by

The trivalent hydrocarbon group may be alkyltryl, aryltryl,arylalkyltryl, alkylaryltryl and hydrocarbon groups having those groupsas the base skeleton. Specific examples of the trivalent hydrocarbongroup are those represented by the following formulae:

The quatravalent hydrocarbon group may be alkyltetraaryl, aryltetraaryl,arylalkyltetraaryl and alkylaryltetraaryl groups and hydrocarbon groupshaving these groups as a base skeleton. Specific examples of thequatravalent hydrocarbon groups are those represented by the followingformulae:

Specific examples of the compound are those having 1 to 1 00, preferably2 to 50, more preferably 1 to 20 oxyalkylene units, such astrimethylolpropanetri(polyethylene glycol acrylate),trimethylolpropanetri (polyethylene glycol methaacrylate),trimethylolpropanetri (polypropylene glycol acrylate),trimethylolpropanetri (polypropylene glycol methaacrylate),tetramethylolmethanetetra(polyethylene glycol acrylate),tetramethylolmethanetetra (polyethylene glycol methaacrylate),tetramethylolmethanetetra(polypropylene glycol acrylate),tetramethylolmethanetetra(polypropylene glycol methaacrylate),2,2-bis[4-(acryloxypolyethoxy)phenyl]propane,2,2-bis[4-(methaacryloxypolyethox y)phenyl]propane,2,2-bis[4-(acryloxypolyisopropoxy)phenyl]propane,2,2-bis[4-(methaacryloxypolyisopropoxy)phenyl]propane and mixturesthereof.

If in formula (22) is 2 or greater, the compound may be those havingdifferent oxyalkylene units from each other, that is, copolymerizedoxyalkylene units which result from alternating-, block- orrandom-copolymerization. Specific examples of such compounds are thosehaving 1 to 50, preferably 1 to 20 of oxyethylene units and 1 to 50,preferably 1 to 20 of oxypropylene units such astrimethylolpropanetri(poly(ethylene.propylene)glycol acrylate),trimethylolpropanetri(poly(etlhylene.propylene)glycol methaacrylate),tetramethylolmethanetetra(poly(ethylene.propylene)glycol acrylate),tetramethylolmethanetetra(poly(ethylene.propylene)glycol acrylate) andmixtures thereof.

There may be used the difunctional modified polyalkyleneoxide of formula(21) and the polyfunctional modified polyalkyleneoxide of formula (22)in combination. When these compounds are used in combination, the weightratio of these compounds is within the range of 0.01/99.9-99.9/0.01,preferably 1/99-99/1, more preferably 20/80-80/20.

A polymeric solid electrolyte containing the above-described modifiedpolyalkylene oxide is prepared by admixing the modified polyalkyleneoxide, a solvent and a supporting electrolyte both described withrespect to the liquid type ion conductive substance so as to obtain aprecursor composition and solidifying the composition. The amount of thesolvent is selected from the range of 50 to 800 percent by weight,preferably 100 to 500 percent by weight per of the total weight of themodified polyalkylene oxide. No particular limitation is imposed on theamount of the supporting electrolyte and it may not be added. The upperlimit is usually 30 percent by weight or less, preferably 20 percent byweight of the amount of the solvent, while the lower limit is 0.1percent by weight or more, preferably 1 percent by weight or more.

If necessary, cross-linkers or polymerization initiators may be added tothe polymeric solid electrolyte containing the modified polyalkyleneoxide.

Cross-linkers which may be added to the polymeric electrolyte areacrylate-based cross-linkers having two or more functional groups.Specific examples are ethylene glycol dimethacrylate, diethylene glycoldimethacrylate, tetraethylene glycol dimethacrylate, ethylene glycoldiacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate,polyethylene glycol dimethacrylate, polyethylene glycol diacrylate,neopentyl glycol diacrylate, 1,6-hexanediol diacrylate,trimethylolpropane trimethacrylate, trimethylolpropane triacrylate,tetramethylolmethane tetracrylate, and tetramethylolmethanetetramethacrylate. These may be used singlely or in combination.

The amount of the cross-linker is 0.01 percent by mol or more,preferably 0.1 percent by mol or more, of 100 percent by mole of thepolymeric urethaneacrylate or modified polyalkylene oxide contained inthe polymeric solid electrolyte. The upper limitis 10 percent by molpreferably 5 percent by mol.

Polymerization initiators which may be added to the polymeric solidelectrolyte are photo-polymerization initiators andthermal-polymerization initiators.

No particular limitation is imposed on the kind of thephoto-polymerization initiators. Therefore, the photo-polymerizationinitiators may be conventional ones which are benzoin-, acetophenone-,benzylketal- or acylphosphine oxide-based. Specific examples of suchphoto polymerization initiators are acetophenone, benzophenone,4-methoxybenzophenone, benzoin methyl ether,2,2-dimethoxy-2-phenyldimethoxy-2-phenylacetophenone, 2-methylbenzoyl,2-hydroxy-2-methyl-1-phenyl-1-on,1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-on,triphenylphospline, 2-chlorothioxantone,2-hydroxy-2-methyl-1-phenylpropane-1-on,1-hydroxycyclohexylphenylketone, 2,2-dimethoxy-2-phenylacetophenone,2-methyl-(4-(methylthio)phenyl)-2-morpholino-1-propanone,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butane-1-on,1-(4-(2-hydroxyethoxy)phenyl)-2-hydroxy-2-methyl-1-on,diethoxyacetophenone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.These may be used singlely or in combination.

Eligible thermal polymerization initiators may be selected from knowninitiators such as peroxide initiators or azo-based initiators. Specificexamples of such peroxide initiators are benzoyl peroxide, methylethylperoxide, t-butylperoxypivalate and diisopropylperoxycarbonate. Specificexamples of such azo-based initiators are2,2′-azobis(2-isobutylonitrile), 2,2′-azobisisobutylonitrile,2,2′-azobis(2,4-dimethylvaleronitrile) and1,1′-azobis(cyclohexane-1-carbonitrile). These may be used singlely orin combination.

The amount of the polymerization initiators is 0.1 part by weight ormore, 0.5 part by weight or more, of 100 parts by weight of thepolymeric urethaneacrylate or modified polyalkylene oxide contained inthe polymeric solid electrolyte. The upper limit is 10 part by weight,preferably 5 part by weight or less.

The polymeric solid electrolyte is solidified by photo- orthermal-curing the polymeric urethaneacrylate or modified alkyleneoxide.

Photo-curing is progressed by irradiating far ultraviolet rays,ultraviolet rays or visible rays to the polymeric solid electrolytecontaining a photo-polymerization initiators. Eligible light sources arehigh voltage mercury lamps, fluorescent lamps and xenon lamps. Althoughnot restricted, the photo polymerization is conducted by irradiatinglight of 100 mJ/cm² or higher, preferably 1,000 J/cm² or higher. Theupper limit is 50,000 mJ/cm², preferably 20,000 mJ/cm².

Thermal curing is progressed by heating the polymeric solid electrolytecontaining a thermal-polymerization initiators at a temperature of 0° C.or higher, preferably 20° C. or higher. The heating temperature is 130°C. or lower, preferably 80° C. or lower. The curing is continued forusually 30 minutes or longer, preferably one hour or longer and 100hours or shorter, preferably 40 hours or shorter.

As described above, the ion conductive layer of the present inventioncontains Compound (A) described above but no particular limitation isimposed on the production method and form thereof. For example, aliquid-type ion conductive substance may be prepared by appropriatelydispersing Compound (A) into the conductive substance. Agelatinized-type liquid ion conductive substance may be prepared bymixing at the precursor stage thereof with Compound (A) such that thecompound is appropriately dispersed or dissolved in the substance. Asolid type ion conductive substance may be prepared by mixing Compound(A) with the solid electrolyte in a unsolidified stage, beforehand andthen solidifying the mixture, whereby the compound is suitably dispersedor dissolved in the substance. Alternatively, in the case of thepolymeric solid electrolyte, Compound (A) is mixed with a solidelectrolyte in a unsolidified state, that is, the aforesaid polymericsolid electrolyte precursor composition and cured whereby the resultingsubstance has the compound suitable dispersed or dissolved therein.

Regardless of whether the ion conductive substance is liquid,gelatinized liquid or solid, the ion conductive layer containingCompound (A) of the present invention preferably contains ultravioletabsorbing agents. Such ultraviolet absorbing agents may bebenzotriazole-, benzophenone-, triazine-, salicylate-, cyanoacrylate-,and oxalic anilide-based compounds. Among these, benzotriazole- andbenzophenone-based compounds are preferred.

Benzotriazole-based compounds are exemplified by compounds representedby the formula

In formula (23), R⁴⁶ is hydrogen, halogen or an alkyl group having 1 to10, preferably 1 to 6 carbon atoms. Specific examples of the halogen arefluorine, chlorine, bromine and iodine. Specific examples of the alkylgroup are methyl, ethyl, propyl, i-propyl, butyl, t-butyl and cyclohexylgroups. Preferred for R⁴⁶ are hydrogen and chlorine. R⁴⁶ is usuallysubstituted at the 4- or 5-position of the benzotriazole ring but thehalogen atom and the alkyl group are usually located at the 5-position.R⁴⁷ is hydrogen or a hydrocarbon group having 1 to 10, preferably 1 to 6carbon atoms. Examples of the hydrocarbon groups are methyl, ethyl,propyl, i-propyl, butyl, t-butyl, t-amyl, cyclohexyl, and1,1-dimethylbenzyl groups. Particularly preferred are t-butyl, t-amyland 1,1-dimethylbenzyl groups. R⁴⁸ is a carboxyl-substituted alkyl(—R—COOH) or a carboxyl-substituted alkylidene group having 2 to 10,preferably 2 to 4 carbon atoms. The alkyl chain portion (—R—) may bemethylene, ethylene, trimethylene, and propylene groups. The alkylidenemay be ethylidene and propylidene groups. R⁴⁸ may be an alkyl group suchas t-butyl, t-amyl, and 1,1,3,3-tetramethylbutyl groups, an alkanoicacid alkyl ester such as propionic acid octyl ester, and arylalkyl groupsuch as 1,1-dimethylbenzyl group.

Specific examples of such benzotriazole-based compounds are3-(5-chloro-2H-benzotriazole-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzenepropanoic acid,3-(2H-benzotriazole-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzeneethanoic acid, 3-(2H-benzotriazole-2-yl)-4-hydroxybenzene ethanoic acid,3-(5-methyl-2H-benzotriazole-2-yl)-5-(1-methylethyl)-4-hydroxybenzenepropanoic acid,iso-octyl-3-(3-(2H-benzotriazole-2-yl)-5-t-butyl-4-hydroxyphenylpropionate,methyl-3-[3-t-butyl-5-(2H-benzotriazole-2-yl)-4-hydroxyphenyl]propionate,2-(5′-methyl-2′-hydroxyphenyl)benzotriazole,2-[2′-hydroxy-3′,5′-bis(α,α-dimethylbenzyl) phenyl]-2H-benzotriazole,2-(2′-hydroxy-5′-t-butylphenyl) benzotriazol,2-(3′,5′-di-t-butyl-2′-hydroxyphenyl) benzotriazole,2-(2′-hydroxy-5′-t-octylphenyl) benzotriazole,2-(3′-dodecyl-5′-methyl-2′-hydroxyphenyl) benzotriazole,2-(2′-hydroxy-3′,5′-di-t-amyl-phenyl)-2H-benzotriazole,2-(2′-hydroxy-3′-(3″,4″,5″,6″-tetrahydrophthalimidemethyl)-5-methylphenyl)benzotriazole,2-(3′-t-butyl-5′-methyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,2-(3′,5′-di-t-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,2-[2-hydroxy-3,5-di(1,1-dimethylbenzyl) phenyl]-2H-benzotriazole,2-[2-hydroxy-3-dimethylbenzyl-5-(1,1,3,3-tetramethylbutyl)phenyl]-2H-benzotriazole,3-(5-chloro-2H-benzotriazole-2-yl)-5-t-butyl-4-hydroxyphenyl propanoicacid octyl ester, and3-(5-chloro-2H-benzotriazole-2-yl)-5-t-butyl-4-hydroxyphenyl-n-propanol.Among these, particularly preferred are3-(5-chloro-2H-benzotriazole-2-yl)-5-t-butyl-4-hydroxyphenylpropanoicacid octyl ester and3-(5-chloro-2H-benzotriazole-2-yl)-5-t-butyl-4-hydroxyphenyl-n-propanol.

Benzophenone-based compounds are exemplified by compounds represented bythe following formulae

In formulae (24)-(27), R⁴⁹ indicates a covalent bond or is methylene,ethylene, or propylene group. R⁵⁰ and R⁵¹ may be the same or differentand are each independently a hydroxyl group or an alkyl or alkoxy grouphaving 1 to 10, preferably 1 to 6 carbon atoms. The group of —R⁴⁹—COOHmay not be present in these formulae. The letters “g′” and “k′” eachdenotes an integer of 0≦g≦3 and 0≦k≦3. Specific examples of the alkylgroup are methyl, ethyl, propyl, i-propyl, butyl, t-butyl, andcyclohexyl groups. Specific examples of the alkoxy group are methoxy,ethoxy, propoxy, i-propoxy, and butoxy groups.

Specific examples of the benzophenone-based compounds are2-hydroxy-4-methoxybenzophenone-5-carboxylic acid,2,2′-dihydroxy-4-methoxybenzophenone-5-carboxylic acid,4-(2-hydroxybenzoyl)-3-hydroxybenzene propanoic acid,2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone,2-hydroxy-4-methoxybenzophenone-5-sulfonic acid,2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone2,2′-dihydroxy-4-methoxybenzophenone,2,2′-dihydroxy-4,4′-methoxybenzophenone,2,2′,4,4′-tetrahydroxybenzophenone,2-hydroxy-4-methoxy-2′-carboxybenzophenone, and2-hydroxy-4-methoxy-5-sulfonbenzophenone, among which preferred is2,2′,4,4′-tetrahydroxybenzophenone.

Examples of the triazine-based compounds are2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[(hexyl)oxy]-phenol,2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,and2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

Examples of the salicylate-based compounds are phenylsalicylate,p-t-butylphenylsalicylate, and p-octylphenylsalicylate.

Examples of the cyanoacrylate-based compounds are2-ethylhexyl-2-cyano-3,3′diphenylacrylate, andethyl-2-cyano-3,3′-diphenylacrylate.

Examples of the oxalic acid anilide-based compounds such as2-ethoxy-2′-ethyle-oxalic acid bisanilide.

In the case where the ion conductive layer contains an ultravioletabsorber, regardless of the kinds thereof, the lower limit amount of theabsorber is 0.1 percent by weight or more, preferably 1 percent byweight or more, while the upper limit is 20 percent by weight or more,preferably 10 percent by weight or more.

The electrochromic device of the present invention may be produced byany suitable method. For instance, in the case where the ion conductivesubstance is liquid type or gelatinized liquid type, the electrochromicdevice of the present invention may be produced by injecting an ionconductive substance having Compound (A) dispersed therein into a spacebetween two electrically conductive substrates disposed so as to opposeto each other and having sealed peripheral edges, by vacuum injection oratmospheric injection or a meniscus method and then sealing theperipheral edges. Alternatively, depending on the type of ion conductivesubstance, the electrochromic device of the present invention may beproduced by forming an ion conductive layer containing Compound (A) overone of the two electrically conductive substrates and then superimposingthe other substrate thereover. Further alternatively, the electrochromicdevice may be produced just like producing a laminated glass using theion conducive substance containing Compound (A) formed into a film.

In the case of using the solid ion conductive substance, particularly apolymeric solid electrolyte containing a urethaneacrylate or a modifiedalkylene oxide, the electrochromic device of the present invention maybe prepared by injecting an unsolidified polymeric solid electrolyteprecursor containing Compound (A) into a space between two electricallyconductive substrates disposed so as to oppose to each other and havingsealed peripheral edges, by vacuum injection or atmospheric injection ora meniscus method and curing the electrolyte with a suitable means aftersealing the injection port.

The ion conductive layer of the electrochromic device according to thepresent invention has an ion conductivity of usually 1×10⁻⁷ S/cm orgreater, preferably 1×10⁻⁶ S/cm or greater, more preferably 1×10⁻⁵ S/cmor greater, at room temperature. The thickness of the ion conductivelayer is usually 1 μm or more, preferably 10 μm or more and 3 mm orless, preferably to 1 mm or less.

The basic structure of the electrochromic device of the presentinvention will be described with reference to the drawings.

The electrochromic device shown in FIG. 3 has an ion conductive layer 3in which Compound (A) is dispersed, sandwiched between a transparentelectrically conductive substance having a transparent substrate 1 and atransparent electrode layer 2 laminated thereover and an electricallyconductive substrate having a transparent or opaque substrate 5 and atransparent, opaque or reflective electrode layer 4.

FIG. 4 shows the structure of a display or a smart window which has anion conductive layer 3 in which Compound (A) is dispersed, sandwiched ina space suitably provided between two transparent electricallyconductive substrates each having a transparent electrode layer 2 formedon one surface of each transparent substrate 1 arranged so as to opposeto each other such that the transparent electrode layers face eachother.

FIG. 5 shows the structure of an electrochromic mirror which has an ionconductive layer 3 in which Compound (A) is dispersed, sandwiched in aspace suitably provided between a transparent electrically conductivesubstrate having a transparent electrode layer 2 on one surface of atransparent substrate 1 and a reflective electrically conductivesubstrate having a transparent electrode layer 4 on one surface of atransparent substrate 5 and a reflective layer 7 on the other surfacethereof.

The electrochromic devices shown in FIGS. 3 through 5 may be produced byany suitable method. For example, in the case of the device shown inFIG. 3, Laminate A is prepared by forming a transparent electrode layer2 over a transparent substrate 1 by the above-mentioned method andfurther providing a belt- or narrow strip-like electrode 8 on oneperipheral edge thereof. Separately from this, Laminate B is prepared byforming a transparent, opaque or reflective electrode layer 4 over on asubstrate 5 and further providing a belt- or narrow strip-like electrode8 on one peripheral edge thereof. An empty cell with an injection portis formed by disposing Laminates A and B so as to oppose to each otherwith a spec of 1 to 1,000 μm and then sealing the peripheral edges witha sealant 6 except a portion for the port. An ion conductive layer 3 isformed by injecting an ion conductive substance into the cell by theabove-mentioned method and then curing the substance thereby producingan electrochromic device.

A spacer may be used in order to keep the space between Laminates A andB constant upon placing them in an opposing relationship. The spacer maybe in the form of beads or sheet formed from glass or polymer. Thespacer may be provided by inserting the beads or sheet into the spacebetween the substrates facing each other or by forming protrusionsformed from an insulate material such as resin, over the electrode ofthe electrically conductive substrate.

Alternatively, Laminate A′ is prepared by forming a transparentelectrode layer 2, a belt- or narrow strip-like electrode 8, and an ionconductive layer 3 on a transparent substrate in this order by theabove-mentioned method. Separately form this, Laminate B′ is prepared bya a transparent, opaque or reflective electrode layer 4 over on asubstrate 5 electrode layer 4 and a belt- or narrow strip-like electrode8 over a substrate 5 by the above-mentioned method. Laminates A′ and B′are disposed in an opposed relation with a space of 1 to 1,000 μm suchthat the ion conductive layer contacts the transparent, opaque orreflective electrode layer. The electrochromic device is then producedby sealing the peripheral edges of the laminates with a sealant 6.

In the case of a smart window shown in FIG. 4, two transparentelectrically conductive substrates are prepared by forming a transparentelectrode layer 2 over one surface of a transparent substrate 1. Afterthis, the smart window is produced by following the same procedures asthose described with respect to the device shown in FIG. 3. Anelectrochromic mirror may be produced by following the same proceduresas those described with respect to the device shown in FIG. 3 afterforming a transparent electrically conductive substrate prepared byforming a transparent electrode layer 2 and a belt- or narrow strip-likeelectrode over a transparent substrate 1 and a reflective electricallyconductive substrate prepared by forming a transparent electrode layerand a belt- or narrow strip-like electrode on one surface of atransparent substrate 1 and a reflective layer 7 on the other surface.

Although not shown in the drawings, the electrode layer and belt- ornarrow strip-like electrode is connected with a lead wire for applyingan electric voltage to the electrochromic device. The lead wire may beconnected directly or thorough a clip-like means (highly-conductivemember such as metal sandwiching the conductive substrate so as tocontact the electrode layer or belt- or narrow strip-like electrode) tothe electrode layer and belt- or narrow strip-like electrode. Noparticular limitation is imposed on the size of clip-like means. Theupper limit length of the clip-like means is generally the length of anyside of a substrate.

FIGS. 3 through 5 show typical examples of the structures of theelectrochromic device of the present invention. If necessary,ultraviolet shielding layers for reflecting or absorbing ultravioletradiation may be added. An electrochromic mirror may additionally havean overcoat layer for protecting the surface the entire mirror layer oreach layer. The ultraviolet shielding layer may be arranged on eitherthe outer surface or transparent electrode surface of the transparentsubstrate 1. The overcoat layer may be arranged on either the outersurface of the transparent substrate 1 or the reflective layer 7.

The electrochromic device of the present invention can be used suitablyfor the production of display devices, smart windows, anti-glare mirrorsfor automobiles and electrochromic mirrors such as decorative mirrorsplaced outdoor. Furthermore, the electrochromic device of the presentinvention excels not only in the basic characteristics but also in theresponse of coloration and decoloration. The electrochromic device ischaracterized by the ability to work with a lower electric voltage thanconventional ones.

When the electrochromic device of the present invention is used as adisplay device, it is used for displaying information at stations,airports, underground shopping malls, office buildings, schools,hospitals, banks, stores (floor directions, price indications, andindications of the state of ticket reservation) and other publicfacilities. It can be also be used as monuments and display means ofequipment such as large-size electronic books, game machines, electronicwatches and clocks, and electronic calendars.

In these cases, monochrome display is possible using single colordevices. Color display is also possible by arranging devices ofdifferent colors. Color display is also possible by arranging the devicebetween a color filter and a light source and using the coloration anddecoloration function as a shutter.

The present invention will now be described with reference to thefollowing examples. Before providing the examples, synthesis examples ofthe ferrocene-bipyridine derivatives used in the present invention areprovided. These examples are not provided to limit the presentinvention.

Synthesis 1

Synthesis of 1-(4-ferrocenylbutyl)-1′-methyl-4,4′-bipyridiniumBis(tetrafluoroborate)

7.9 g (30.8 mmol) ferrocenylbutanol was dissolved in 200 ml pyridine and8.6 g (45.1 mmol) tosylchloride was slowly added thereto while coolingwith ice, followed by 7-hour stirring.

After the reaction, the mixture was quenched with water and extractedwith chloroform. Thereafter, the organic layer was washed with dilutehydrochloric acid, a saturated aqueous solution of NaHCO₃ and water andthen was dried, filtrated and vacuum-concentrated. The resulting residuewas refined in a silica gel column (200 g, hexane/ethylether=6/1)thereby 8.6 g (20.9 mmol, yield 68%) 4-ferrocenylbutyltosylate.

4.5 g (10.9 mmol) of the tosylate thus obtained and 17.0 g (0.11 mol)4,4′-bipyridine were dissolved in toluene and stirred at a temperatureof 60° C. for 4 days. The precipitate thus formed was washed withtoluene and isopropanol (IPA) thereby obtaining 5.0 g (8.78 mmol, yield81%) 1-(4-ferrocenylbutyl)-4-(4′-pyridyl)-pyridinium tosylate, i.e., amonopyridinium salt.

5.0 g (8.78 mol) of the monopyridinium salt were dissolved in 100 ml DMFand 8.2 ml (0.132 mol) methyl iodine was added thereto. After themixture was stirred at room temperature for 15 hours, the reactionsolution was poured in 300 ml ether. The precipitate was filtered anddried thereby obtaining 6.0 g (8.43 mmol, yield 96%)1-(4-ferrocenylbutyl)-1′-methyl-4,4′-bipyridinium tosylate iodiderepresented by the following formula:

¹H NMR Spectrum (ppm)

9.38, 8.71(m, 8H), 7.49, 7.11(m, 4H), 4.65(t,

2H), 4.45(s, 3H), 4.10, 4.05(s, 9H), 2.35(t,

2H), 2.31(s, 3H), 2.05(m, 2H), 1.53(m, 2H)

6.0 g (8.43 mmol) of the1-(4-ferrocenylbutyl)-1′-methyl-4,4′-bipyridinium tosylate iodideobtained above was dissolved in 100 ml water by heating and 15 ml of asaturated aqueous solution of NaBF₄ was added thereto. The precipitatewas filtered and recrystallized with water thereby obtaining 4.3 g (7.34mmol, yield 87%) ferrocene-bipyridine derivative corresponding toCompound (A) of the present invention.

The followings are the chemical formula, elemental analysis results, andNMR spectrum of the ferrocene-bipyridine derivative, i.e.,1-(4-ferrocenylbutyl)-1′-methyl-4,4′-bipyridiniumbis(tetrafluoroborate).

Elemental analysis Calculated: C:51.24, H:4.82, N:4.78 Measured:C:51.15, H:4.78, N: 4.60

¹H NMR Spectrum 9.40, 8.73(m, 8H), 4.68(t, 2H), 4.45(s, 3H), 4.10,4.05(s, 9H), 2.35(t, 2H), 2.00(m, 2H) 1.51(m, 2H)

¹³C NMR Spectrum 148.57, 148.17, 146.60, 145.73, 126.54, 126.04 88.04,68.28, 67.75, 66.91, 60.78, 48.01, 30.68 28.31, 26.93

The NMR spectrum of the ferrocene-bipyridine derivative is shown in FIG.1.

Synthesis 2

Synthesis of 1-(4-ferrocenylbutyl)-1′-heptyl-4,4′-bipyridiniumBis(tetrafluoroborate)

2.8 g (4.9 mmol) of the monopyridinium salt obtained above was dissolvedin 40 ml DMF and 8 ml (0.049 mol) heptyl iodine was added thereto. Afterthe mixture was stirred at a temperature of 60° C. for 3 hours, thereaction solution was poured in 200 ml ether. The precipitate wasfiltered and dried thereby obtaining 2.0 g (2.8 mmol, yield 57%)1-(4-ferrocenylbutyl)-1′-heptyl-4,4′-bipyridiniumtosylate iodide, i.e.,a bipyridinium salt.

¹H NMR Spectrum (ppm)

9.37, 8.77(m, 8H), 7.49, 7.11(m, 4H), 4.69(t,

4H), 4.10, 4.05(s, 9H), 2.37(t, 2H), 2.31(s, 3H)

1.99(m, 2H), 1.52(m, 2H), 1.27(m, 8H), 0.87(t,

3H)

2.2 g (2.7 mmol) of the bipyridinium salt thus obtained were dissolvedin 15 ml of a mixed solution of water/MeOH by heating, and 5 ml of asaturated aqueous solution of NaBF₄ was added thereto. The precipitatewas filtered and recrystallized with water thereby obtaining 1.7 g (2.5mmol, yield 93%)of a ferrocene-bipyridine derivative which is a novelcompound of the present invention.

Elemental analysis Calculated: C:55.66, H:6.02, N:4.18 Measured:C:55.49, H:5.96, N: 4.28

¹H NMR Spectrum (ppm) 9.37, 8.77(m, 8H), 4.69(t, 2H), 4.10, 4.05(s, 9H),2.37(t, 2H), 1.99(m, 2H), 1.52(m, 2H), 1.27(m, 8H), 0.87(t, 3H)

¹³C NMR Spectrum (ppm) 148.60, 145.69, 126.60, 126.55, 88.04, 68.27,67.74, 66.99, 60.92, 60.80, 30.97, 30.68, 28.31, 28.01, 26.93, 25.35,21.92, 13.86

Synthesis 3

Synthesis of 1-(4-ferrocenylbutyl)-1′-heptyl-4,4′-bipyridiniumbis(tetrafluoroborate)

The procedures of Synthesis 2 were followed but benzylbromide was usedinstead of heptyl iodine thereby obtaining a bipyridinium salt. Anionexchange was conducted like Synthesis 2 thereby obtainingferrocene-bipyridine in a 46% yield in a two-step reaction.

Elemental Analysis Calculated: C:56.24, H:4.87, N:4.23 Measured:C:56.17, H:4.76, N: 4.41

¹H NMR Spectrum (ppm) 9.36, 8.78(m, 8H), 7.52-7.05(m, 5H), 6.01(s, 3H)4.62(t, 2H), 4.10, 4.05(s, 9H), 2.38(t, 2H), 2.02(m, 2H), 1.51(m, 2H),

¹³C NMR Spectrum (ppm) 148.62, 148.21, 146.51, 145.23, 142.52, 129.01,128.50, 128.21, 126.54, 126.04, 88.00, 68.18, 67.65, 66.94, 62.98,48.33, 30.52, 28.33, 26.95

Synthesis 4

Synthesis of 1-(ferrocenylmethyl)-1′-methyl-4,4′-bipyridiniumbis(tetrafluoroborate)

2.5 g (63.3 mmol) hydrogenated lithium aluminum was dissolved in 50 gether and 100 ml of an ether solution dissolving 10.8 g of (46.9 mmol)ferrocenyl carboxylic acid was slowly added thereto, followed bystirring at room temperature. After the reaction, the mixture wasquenched with water and extracted with chloroform. Thereafter, theorganic layer was washed with dilute hydrochloric acid, and a saturatedaqueous solution of NaHCO₃ and then was dried, filtrated andvacuum-concentrated thereby obtaining an alcohol compound.

The resulting alcohol compound was dissolved in 100 ml ether and 5.0 gsodium chloride was added thereto, followed by blowing hydrogen chlorideunder a nitrogen atmosphere. After the reaction, the precipitate wasfiltered and vacuum-concentrated thereby obtaining chloromethylferrocene.

The chloromethyl ferrocene and 70.0 g(0.45 mol) 4,4′-bipyridine weredissolved in toluene and stirred for 24 hours. The precipitate thusformed was filtered and washed with toluene and IPA thereby obtaining7.8 g (20.2 mmol, yield 43%) of a monopyridinium salt.

¹H NMR Spectrum (ppm)

9.09, 8.81, 8.45, 7.92(m, 8H), 5.86(s, 2H),

4.72, 4.63, 4.51(s, 9H)

7.8 g (20.2 mmol) of the monopyridinium salt obtained above wasdissolved in 100 ml DMF and 12.2 ml (0.20 mol) methyl iodine was addedthereto. The mixture was stirred at room temperature for 15 hours. Afterthe reaction, the reaction solution was poured in 300 ml ether. Theprecipitate was filtered and dried thereby obtaining 10.0 g (18.8 mmol,yield 94%) of a bipyridinium salt.

¹H NMR Spectrum

9.15, 8.74(m, 8H), 5.71(s, 2H), 4.81(s, 3H),

4.66, 4.53, 4.49 (s, 9H)

10.0 g (18.8 mmol) bipyridinium salt obtained above was dissolved in 100ml water by heating, and 15 ml of a saturated aqueous solution of NaBF₄were added thereto. The precipitate was filtered and recrystallized withwater thereby obtaining 6.2 g (11.4 mmol, yield 61%) of aferrocene-bipyridine derivative of the present invention.

Elemental analysis Calculated: C:48.58, H:4.08, N:5.15 Measured:C:48.30, H1:4.28, N: 5.11

¹H NMR Spectrum (ppm) 9.17, 8.72(m, 8H), 5.67(s, 2H), 4.76(s, 3H), 4.65,4.51, 4.46(s, 9H)

¹³C NMR Spectrum (ppm) 151.23, 146.26, 145.97, 127.8, 126.5, 78.5,71.10, 70.62, 70.2, 62.5, 49.21

Synthesis 5

Synthesis of 1-(8-ferrocenyloctyl)-1′-methyl-4,4′-bipyridiniumbis(tetrafluoroborate)

5.1 g (16.2 mmol) ferrocenyloctanol was dissolved in 150 ml pyridine and4.7 g (24.7 mmol) tosylchloride was slowly added thereto while coolingwith ice, followed by stirring for a whole day and night. After thereaction, the mixture was quenched with water and extracted withchloroform. Thereafter, the organic layer was washed with dilutehydrochloric acid and a saturated aqueous solution of NaHCO₃ and thenwas dried, filtrated and vacuum-concentrated. The resulting residue wasrefined in a silica gel column (200 g, hexane/ethylether=6/1) thereby4.9 g (10.5 mmol, yield 65%) of a tosyl compound.

4.9 g (10.5 mmol) of the tosyl compound and 17.0 g (0.11 mol)4,4′-bipyridine were dissolved in toluene and heated and stirred at 60°C. for 4 days. The precipitate thus formed was filtered and washed withtoluene and IPA thereby obtaining 4.2 g (6.72 mmol, yield 64%) of amonopyridinium salt.

4.2 g (6.72 mmol) of the monopyridinium salt obtained above weredissolved in 100 ml DMF, and 8.0 ml (0.128 mol) methyl iodine was addedthereto. The mixture was stirred at room temperature for a whole day andnight. The reaction solution was poured in 300 ml ether. The precipitatewas filtered and dried, thereby obtaining 4.0 g (5.22 mmol, yield 78%)of the intended bipyridinium salt.

¹H NMR Spectrum (ppm)

9.42, 8.81(m, 8H), 7.40, 7.15(m, 4H), 4.73(t,

2H), 4.52(s, 3H), 4.11, 4.05(s, 9H), 2.32(s,

3H), 2.12(t, 2H), 1.82-1.10(m, 12H)

4.0 g (5.22 mmol) of the resulting bipyridinium salt were dissolved in100 ml water by heating, and 15 ml of a saturated aqueous solution ofNaBF₄ were added thereto. The precipitate was filtered andrecrystallized with water thereby obtaining 3.1 g (4.83 mmol, yield 93%)ferrocene-bipyridine derivative of the present invention.

Elemental Analysis Calculated: C:54.25, H:5.65, N:4.36 Measured:C:53.99, H:5.47, N: 4.46

¹H NMR Spectrum (ppm) 9.42, 8.81(m, 8H), 4.73(t, 2H), 4.52(s, 3H), 4.11,4.05(s, 9H), 2.12(t, 2H), 1.82-1.10(m, 12H)

¹³C NMR Spectrum (ppm) 150.21, 148.53, 145.10, 126.62, 126.50, 87.34,68.22, 67.70, 67.02, 60.51, 47.21, 30.84, 28.52, 28.33, 28.21, 28.15,27.42, 25.35

Synthesis 6

50 g (0.32 mol) 4,4′-bipyridyl and 65 g (0.32 mol)2,4-dinitrochlorobenzene were dissolved in 300 ml ethanol andheat-refluxed for 24 hours. After the reaction, the reaction solutionwas poured in 1.5 liter ether. The precipitate was recovered therebyobtaining 70 g (0.19 mol) of an N-(2,4-dinitrophenyl)-bipyridinium salt.

40 g (0.11 mol) of the N-(2,4-dinitrophenyl)-bipyridinium salt and 21 g(0.22 mol) aniline were dissolved in 300 ml water and heat-refluxed for2 days. After the reaction, the residue obtained by vacuum-concentrationwas dissolved and precipitated in ether again thereby obtaining 29 g(0.15 mol) of the intended N-phenyl-pyridinium salt.

¹H NMR Spectrum

9.55(2H), 8.91(2H), 8.81(2H), 7.98-7.94(2H),

7.78-7.76(3H)

Elemental analysis

Calculated: C:71.51, H:4.88, N:10.42

Measured: C:71.02, H:4.95, N:10.68

13.5 g (52.3 mmol) ferrocenylbutanol and 23.5 g (0.16 mol) sodium iodinewere dissolved in 200 ml acetonitrile and 20 ml (0.16 mol)trimethylsilylchloride was slowly added thereto, followed by 5-hourstirring. After the reaction, the mixture was diluted with ether,quenched with water, and extracted with ether. The organic layer waswashed with water and a dilute aqueous solution of Na₂S₂O₃ and thendried, filtered and vacuum-concentrated. The resulting residue wasrefined in a silica gel column (200 g, hexane/ethylether=6/1) therebyobtaining 10.6 g (28.8 mol, yield 55%) 4-ferrocenylbutyliodide.

¹H NMR Spectrum 4.05, 4.00(9H), 3.18(2H), 2.36(2H), 1.81(2H), 1.60(2H)

5 g (18.6 mmol) N-phenyl-pyridinium salt and 6.8 g (18.6 mmol) of the4-ferrocenylbutyliodide were dissolved in 50 ml ethanol and stirred at atemperature of 60° C. for 2 days. The mixture was poured in ether. Theprecipitate was recovered and refined by further precipitating inmethanol/ethanol thereby obtaining a bipyridinium salt.

¹H NMR Spectrum 9.67(2H), 9.41(2H), 8.94-89(4H), 7.97, 7.81(5H),4.74(2H), 4.11, 4.00(9H), 2.39(2H), 2.04(2H), 1.55(2H)

Elemental Analysis Calculated: C:56.59, H:4.75, N:4.40 Measured:C:56.45, H:4.85, N:4.51

Salt Exchange of N-(4-ferrocenylbutyl)-N′-phenyl-bipyridinium Salt

2 g (3.1 mmol) of the bipyridinium salt was dissolved in water and asaturated aqueous solution fo NaBF₄ was added thereto. The precipitatewas recovered thereby obtaining the intended bipyridinium salt.

¹H NMR Spectrum 9.65(2H), 9.40(2H), 8.94-8.87(4H), 7.97-7.95,7.83-7.79(5H), 4.73(2H), 4.13, 4.00(9H), 2.36(2H), 2.00(2H), 1.54(2H)

Elemental analysis Calculated: C:55.60, H:4.67, N:4.32 Measured:C:55.42, H:4.77, N:4.57

Synthesis 7

30 g (84 mmmol) N-(2,4-dinitrophenyl)-pyridinium salt and 20 g (0.16mol) p-anisidine were dissolved in 300 ml water and heat-refluxed for 2days.

After the reaction, the mixture was vacuum-concentrated. The resultingresidue was dissolved in methanol and refined by further precipitatingin ethanol thereby obtaining 21 g(71 mmol) of the intendedN-methoxyphenyl-pyridinium salt.

¹H NMR Spectrum 9.45(2H), 8.90(2H), 8.75(2H), 8.14(2H), 7.90(2H),7.30(31H), 3.91(31H)

Elemental Analysis Calculated: C:68.34, H:5.06, N:9.38 Measured:C:68.02, H:4.97, N:9.11

Synthesis of N-(4-ferrocenylbutyl)-N′-methoxyphenyl-bipyridinium Salt

5 g (16.7 mmol) N-methoxyphenyl-pyridinium salt and 6.1 g (16.6 mmol)4-ferrocenylbutyliodide were dissolved in 50 ml ethanol and stirred at atemperature of 60° C. for 2 days.

After the reaction, the mixture was poured in ether, and the precipitatewas recovered and refined by further precipitating in methanol/ethanolagain.

¹H NMR Spectrum 9.62(2H), 9.42(2H), 8.90(4H), 7.91, 7.32(4H), 4.74(2H),4.11, 4.00(9H), 3.91(3H), 2.38(2H), 2.04(2H), 1.55(2H)

Elemental Analysis Calculated: C:55.84, H:4.84, N:4.20 Measured:C:55.65, H:4.85, N:4.25

Salt Exchange of N-(4-ferrocenylbutyl)-N′-methoxyphenyl-bipyridiniumSalt

2 g (3.0 mmol) of the bipyridinium salt was dissolved in water, and asaturated aqueous solution of NaBF₄ was added thereto. The precipitatedwas recovered thereby obtaining the intended bipyridinium salt.

¹H NMR Spectrum 9.64(2H), 9.39(2H), 8.92(4H), 7.91, 7.31(4H), 4.72(2H),4.14, 4.00(9H), 3.92(3H), 2.35(2H), 2.04(2H), 1.54(2H)

Elemental Analysis Calculated: C:54.91, H:4.76, N:4.13 Measured:C:55.05, H:4.71, N:4.35

Synthesis 8

2.5 g (63.3 mmol) hydrogenated lithium aluminum was dissolved in 50 gether, and 100 ml of an ether solution dissolving 10.8 g (46.9 mmol)ferrocenyl carboxylic acid was slowly added thereto, followed bystirring at room temperature.

After the reaction, the mixture was quenched with water and extractedwith chloroform. The organic layer was washed with dilute hydrochloricacid, a saturated aqueous solution of NaHCO₃, and water and then dried,filtered and vacuum-concentrated thereby obtaining an alcohol compound.

The resulting alcohol compound was dissolved in 100 ml ether and 5.0 gcalcium chloride was added thereto, followed by blowing hydrogenchloride under a nitrogen atmosphere.

After the reaction, the reaction product was filtered andvacuum-concentrated thereby obtaining the intendedchloromethylferrocene.

Synthesis of N-(ferrocenylmethyl)-N′-phenyl-bipyridinium Salt

8.7 g (37 mmol) of the chloromethylferrocene thus obtained and 10 g (37mmol) N-phenyl-pyridinium salt were dissolved in 50 ml ethanol andstirred at room temperature for 4 days.

After the reaction, the mixture was poured in ether. The precipitate wasrecovered and refined by further precipitating in methanol/ethanol.

¹H NMR Spectrum (ppm) 9.65(2H), 9.40(2H), 8.94-8.87(4H), 7.97-7.95,7.83-7.79(5H), 5.82(s, 2H), 4.70, 4.68-4.45, (s, 9H)

Elemental analysis Calculated: C:64.44, H:4.81, N:5.57 Measured:C:64.15, H:4.67, N:5.31

Synthesis 9

5.1 g (16.2 mmol) ferrocenyloctanol was dissolved in 150 ml pyridine,and 4.7 g (24.7 mmol) tosylchloride was slowly added thereto whilecooling with ice. Thereafter, the mixture was stirred for a whole dayand night.

After the reaction, the mixture was quenched with water and extractedwith chloroform. The organic layer was washed with dilute hydrochloricacid, a saturated aqueous solution of NaHCO₃, and water and then dried,filtered and vacuum-concentrated. The resulting residue was refined in asilica gel column (200 g, hexane/ethylether=6/1) thereby obtaining 4.9 g(10.5 mmol, yield 65%) of the intended tosyl compound.

Synthesis of N-(8-ferrocenyloctyl)-N′-phenyl-bipyridinium Salt

4.9 g (10.5 mmol) of the tosyl compound thus obtained and 10 g (37 mmol)N-phenyl-pyridinium salt were dissolved in 50 ml ethanol and stirred ata temperature of 60° C. for 4 days.

After the reaction, the mixture was poured in ether. The precipitate wasrecovered and refined by further precipitating in methanol/ethanol.

¹H NMR Spectrum 9.64(2H), 9.39(2H), 8.92(4H), 8.02-7.82(9H), 4.67(2H),4.12, 3.98(9H), 2.35(2H), 2.24(3H), 2.10-1.42(12H)

Elemental analysis Calculated: C:66.80, H:6.15, N:3.80, S:4.35 Measured:C:66.67, H:6.07, N:3.92, S:3.98

Salt Exchange of N-(8-ferrocenyloctyl)-N′-phenyl-bipyridinium Salt

3 g (4.1 mmol) of the bipyridinium salt were dissolved in water, and asaturated aqueous solution of NaBF₄ was added thereto. The precipitatewas recovered thereby obtaining the intended bipyridinium salt.

¹H NMR Spectrum 9.61(2H), 9.37(2H), 8.91(4H), 8.08-7.78(9H), 4.68(2H),4.14, 4.00(9H), 2.33(2H), 2.21(3H), 2.12-1.54(12H)

Elemental analysis Calculated: C:58.00, H:5.44, N:3.98 Measured:C:58.05, H:5.27, N:3.89

Synthesis 10

50 g (0.32 mol) 4,4′-bipyridyl and 36 g (0.32 mol) 2-chloropyridine weredissolved in 300 ml ethanol and heat-refluxed for 4 days. Thereafter,the reaction solution was poured in 1.5 liter ether. The precipitate wasrecovered thereby obtaining 54 g (0.20 mol) of anN-(2-pyridyl)-bipyridiniumn salt.

Synthesis of 4-ferrocenylbutyl Iodide

13.5 g (52.3 mmol) ferrocenylbutanol and 23.5 g (0.16 mol) sodium iodinewere dissolved in 200 ml acetonitrile, and 20 ml (0.16 mol)trimethylsilylchloride were slowly added thereto, followed by 5-hourstirring. After the reaction, the reaction solution was diluted withether, quenched with water and extracted with ether. The organic layerwas washed with water and a dilute aqueous solution of Na₂S₂O₃ in turnand dried, filtered and vacuum-concentrated.

The resulting residue was refined in a silica gel column (200 g,hexane/ethylether=6/1) thereby obtaining 10.6 g (28.8 mol, yield 55%) ofthe intended iodine compound.

¹H NMR Spectrum 4.05, 4.00(9H), 3.18(2H), 2.36(2H), 1.81(2H), 1.60(2H)

Synthesis of N-4-(ferrocenylbutyl)-N′-2-pyridyl-bipyridinium Salt

5 g (18.5 mmol) of the N-2-pyridyl-bipyridinium salt and 10.0 g (27.2mmol) 4-ferrocenylbutyliodide were dissolved in 50 ml ethanol andstirred at a temperature of 50° C. for 2 days. The reaction solution waspoured in ether. The precipitate was recovered and refined by furtherprecipitating in methanol/ether thereby obtaining a bipyridinium salt.

¹H NMR Spectrum 9.57(2H), 9.34(2H), 9.10-9.01(5H), 8.05-7.85(3H),4.71(2H), 4.11, 4.00(9H), 2.31(2H), 2.00(2H), 1.52(2H)

Elemental analysis Calculated: C:54.61, H:4.58, N:6.59 Measured:C:54.48, H:4.75, N:6.51

Salt Exchange of N-(4-ferrocenylbutyl)-N′-2-pyridyl-bipyridinium Salt

3 g (4.7 mmol) of the bipyridinium salt was dissolved in water, and asaturated aqueous solution of NaBF₄ was added thereto. The precipitatewas recovered thereby obtaining the intended bipyridinium salt.

¹H NMR Spectrum 9.45(2H), 9.26(2H), 9.08-8.98(5H), 7.95-7.81(3H),4.69(2H), 4.11, 4.00(9H), 2.31(2H), 2.00(2H), 1.55(2H)

Elemental analysis Calculated: C:53.67, H:4.50, N:6.47 Measured:C:53.45, H:4.71, N:6.52

Synthesis 11

50 g (0.32 mol) 4,4′-bipyridyl and 36 g (0.32 mol) 2-chloropyrimidinewere dissolved in 300 ml ethanol and heat-refluxed for 4 days.Thereafter, the reaction solution was poured in 1.5 liter ether. Theprecipitate was recovered thereby obtaining 54 g (0.20 mol) of anN-(2-pyrimidyl)-bipyridiniuim salt.

Synthesis of N-4-(ferrocenylbutyl)-N′-2-pyrimidyl-bipyridinium Salt

5 g (18.5 mmol) of the N-2-pyrimidyl-pyridinium salt and 12.0 g (32.6mmol) of the 4-ferrocenylbutyliodide were dissolved in 50 ml ethanol andstirred at a temperature of 50° C. for 2 days. Thereafter, the reactionsolution was poured in ether. The precipitate was recovered and refinedby further precipitating in methanol/ether thereby obtaining abipyridinium salt.

¹H NMR Spectrum 9.64(2H), 9.31(2H), 9.10-9.02(6H), 7.82(1H), 4.72(2H),4.13, 4.00(9H), 2.34(2H), 2.02(2H), 1.56(2H)

Elemental analysis Calculated: C:52.65, H:4.42, N:8:77 Measured:C:52.46, H:4.55, N:8.75

Salt Exchange of N-(4-ferrocenylbutyl)-N′-2-pyrimidyl-bipyridinium Salt

3 g (4.7 mmol) of the bipyridinium salt were dissolved in water, and asaturated aqueous solution of NaBF₄ was added thereto. The precipitatewas recovered thereby obtaining the intended bipyridinium salt.

¹H NMR Spectrum 9.68(2H), 9.261(2H), 9.10-9.00(6H), 7.85(1H), 4.72(2H),4.11, 4.00(9H), 2.31(2H), 2.02(2H), 1.56(2H)

Elemental analysis Calculated: C:51.74, H:4.34, N:8.62 Measured:C:51.67, H:4.17, N:8.52

Synthesis 12

5 g (18.5 mmol) N-2-pyrimidyl-bipyridinium salt and 8.2 g (35.0 mmol)4-ferrocenylmethylchloride were dissolved in 50 ml THF and stirred at atemperature of 50° C. for 2 days. Thereafter, the reaction solution waspoured in ether. The precipitate was recovered and refined by furtherprecipitating in methanol/ethanol thereby obtaining a bipyridinium salt.

¹H NMR Spectrum 9.64(2H), 9.31(2H), 9.10-9.00(6H), 7.81(1H), 5.72(2H),4.71, 4.50-4.40(9H)

Elemental analysis Calculated: C:59.43, H:4.39, N:11.09 Measured:C:59.23, H:4.55, N:11.21

Synthesis 13

50 g (0.24 mmol) of an N-methylbipyridinium salt and 49 g (0.24 mmol)2,4-dinitrochlorobenzene were dissolved in 500 ml ethanol andheat-refluxed for 24 hours. The reaction solution was poured in 1.5liter ether. The precipitate was recovered thereby obtaining 61 g (0.15mol) of an N-(2,4-dinitrophenyl)-bipyridinium salt.

Synthesis of N-aminiophenyl-bipyridinium Salt

30 g (73 mmol) of the N-(2,4-dinitrophenyl)-bipyridinium salt and 12 g(0.11 mol) phenylenediamine were dissolved in 300 ml water andheat-refluxed for 2 days. Thereafter, the reaction solution wasvacuum-concentrated. The resulting residue was dissolved in methanol andrefined by further precipitating in ether thereby obtaining 16 g (48mmol) of the intended N-aminophenyl-pyridinium salt.

¹H NMR Spectrum 9.65(2H), 9.45(2H), 8.98(4H), 8.18-7.94(4H), 4.32(3H)

Elemental analysis Calculated: C:61.09, H:5.13, N:12.57 Measured:C:61.02, H:4.95, N:12.68

Synthesis of N-(4-ferrocenylbutyl)aminophenyl-N′-methyl-bipyridiniumSalt

5 g (15 mmol) of the N-aminophenyl-pyridinium salt, 5.5 g (15 mmol)4-ferrocenylbutyliodide, and Na₂CO₃ were dissolved in 50 ml ethanol andstirred at a temperature of 60° C. for a whole day and night.Thereafter, the reaction solution was poured in ether. The precipitatewas recovered and dissolved in water by heating, followed by theaddition of NaBF₄ thereby recovering the precipitate. The precipitatewas refined by further precipitating in methanol/ethanol therebyobtaining the intended bipyridinium salt.

¹H NMR Spectrum 9.57(2H), 9.45(2H), 8.92-8.93(4H), 8.21-7.95(4H),4.32(3H), 4.21, 4.07(9H), 3.21(2H), 2.45(2H), 2.00(2H), 1.51(2H)

Elemental analysis Calculated: C:54.99, H:4.91, N:6.21 Measured:C:54.75, H:4.85, N:6.41

Synthesis 14

50 g (0.17 mol) N-heptylpryridinium salt and 35 g (0.17 mol)2,4-dinitrochlorobenzene were dissolved in 400 ml ethanol andheat-refluxed for 24 hours. The reaction solution was poured in 1.5liter ether. The precipitate was recovered thereby obtaining 49 g (0.10mol) of an N-(2,4-dinitrophenyl)-bipyridinium salt.

Synthesis of N-aminophenyl-bipyridinium Salt

20 g (40 mmol) of the N-(2,4-dinitrophenyl)-bipyridinium salt and 8.7 g(80 mmol) phenylenediamine were dissolved in 200 ml water andheat-refluxed for 2 days. Thereafter, the reaction solution wasvacuum-concentrated. The resulting residue was dissolved in methanol andrefined by further precipitating in ether thereby obtaining 12.5 g (30mmol)of the intended N-aminophenyl-pyridinium salt.

¹H NMR Spectrum 9.65(2H), 9.45(2H), 8.98(4H), 7.98-7.94(4H), 4.67(2H),2.00(2H), 1.34(8H), 0.92(3H)

Elemental analysis Calculated: C:66.02, H:6.99, N:10.04 Measured:C:65.91, H:6.89,N:10.36

Synthesis of N-(4-ferrocenylbutyl)aminophenyl-N′-heptyl-bipyridiniumSalt

5 g (12 mmol) of the N-aminophenyl-bipyridinium salt, 4.4 g (12 mmol)4-ferrocenylbutyliodide, and Na₂CO₃ were dissolved in 50 ml ethanol andstirred at a temperature of 60° C. for a whole day and night.Thereafter, the reaction solution was poured in ether. The precipitatewas recovered and dissolved in water by heating, followed by theaddition of NaBF₄ thereby recovering the precipitate. The precipitatewas refined by further precipitating in methanol/ether thereby obtainingthe intended bipyridinium salt.

¹H NMR Spectrum 9.67(2H), 9.41(2H), 8.99-8.93(4H), 8.13-7.95(4H),4.67(4H), 4.07, 4.00(9H), 3.25(2H), 2.34(2H), 2.00(4H), 1.51(2H),1.32(8H), 0.95(3H)

Elemental analysis Calculated: C:58.38, H:5.96, N:5.52 Measured:C:58.11, H:5.85, N:5.40

Synthesis 15

20 g (49 mmol) N-(2,4-dinitrophenyl)-bipyridinium salt and 18.0 g (0.1mol) benzidine were dissolved in 300 ml water and heat-refluxed for 2days. The reaction solution was vacuum-concentrated. The resultingresidue was dissolved in methanol and refined by further precipitatingin ether thereby obtaining 12 g (30 mmol) of the intendedN-aminobiphenyl-pyridinium salt.

¹H NMR Spectrum 9.67(2H), 9.42(2H), 9.00-8.83(4H), 8.12-7.82(4H),7.65-7.25(4H), 4.32(3H)

Elemental analysis Calculated: C:67.32, H:5.16, N:10.24 Measured:C:66.98, H:5.00, N:10.06

Synthesis of N-(4-ferrocenylbutyl)aminobiphenyl-N′-methyl-bipyridiniumSalt

10 g (24 mmol) of the N-aminophenyl-pyridinium salt, 8.8 g (24 mmol)4-ferrocenylbutyliodide, and Na₂CO₃ were dissolved in 50 ml ethanol andstirred at a temperature of 60° C. for a whole day and night. Thereaction solution was poured in ether. The precipitate was recovered anddissolved in water by heating, followed by the addition of NaBF₄ therebyrecovering the precipitate. The precipitate was refined by furtherprecipitating in methanol/ether thereby obtaining the intendedbipyridinium salt.

¹H NMR Spectrum 9.57(2H), 9.54(2H), 8.90-8.87(4H), 8.21-7.85(4H),7.54-7.34(4H), 4.35(3H), 4.12, 4.00(9H), 3.31(2H), 2.38(2H), 2.03(2H),1.55(2H)

Elemental analysis Calculated: C:59.00, H:4.95, N:5.58 Measured:C:58.77, H:4.78, N:5.31

Synthesis 16

Synthesis of 1,1′-bis(4-ferrocenylbutyl)-4,4′-bipyridinium Diiodide

1.2 g (3.26 mmol) 4-ferrocenylbutyliodide which can be obtained from4-ferrocenylbutanol in a conventional manner and 0.23 g (1.47 mmol)4,4′-bipyridine were dissolved in 20 ml DMF and heat-refluxed at atemperature of 80° C. for 2 days.

After the reaction, the reaction solution was disposed still to becooled off and then poured in ether. The precipitate was filtered andwashed with isopropylalcohol (IPA) and recrystallized with water therebyobtaining 0.9 g (1.01 mmol, yield 69%) of the intended bipyridiniumsalt.

Elemental analysis Calculated: C:51.15, H:4.74, N:3.14 Measured:C:51.24, H:4.78, N:3.60

¹H NMR Spectrum (ppm) 9.21, 8.73(m, 8H), 4.64(t, 24), 4.10, 4.05(s,18H), 2.31(t,4H), 2.05(m, 4H), 1.56(m, 4H)

¹³C NMR Spectrum (ppm) 148.17, 145.73, 126.04, 88.14, 68.18, 67.75,66.87, 60.58, 30.52, 28.31, 26.94

Synthesis 17

Synthesis of 1,1′-bis(4-ferrocenylbutyl)-4,4′-bipyridiniumbis(tetrafluoroborate)

0.5 g (0.56 mmol) of the bipyridinium salt obtained by Synthesis 16 wasdissolved in 10 ml water and 2 ml of a saturated aqueous solution ofNaBF₄ were added thereto.

The precipitate was recovered and recrystallized with water therebyobtaining the intended bipyridinium salt.

Elemental analysis Calculated: C:56.20, H:5.21, N:3.45 Measured:C:56.05, H:5.05, N:3.51

¹H NMR Spectrum (ppm) 9.23, 8.71(m, 8H), 4.65(t, 24), 4.11, 4.05(s,18H), 2.31 (t, 4H), 2.00(m, 4H), 1.55(m, 4H)

¹³C NMR Spectrum 148.15, 145.73, 126.21, 88.18, 68.20, 67.74, 66.88,60.58, 30.51, 28.30, 26.90

Synthesis 18

Synthesis of 1,1′-bis(8-ferrocenyloctyl)-4,4′-bipyridinium Diiodide

2.5 g (5.89 mmol) 8-ferrocenyloctyliodide which can be obtained from8-ferrocenyloctanol in a conventional manner and 0.44 g (2.82 mmol)4,4′-bipyridine were dissolved in 30 ml DMF and heat-refluxed at atemperature of 80° C. for 2 days.

After the reaction, the reaction solution was disposed still to becooled off and then poured in ether. The precipitate was filtered andwashed with IPA, followed by recrystallization with water therebyobtaining 1.5 g (1,49 mmol, yield 53%) of the intended bipyridiniumsalt.

Elemental analysis Calculated: C:55.00, H:5.82, N:2.79 Measured:C:55.03, H:5.76, N:2.51

¹H NMR Spectrum (ppm) 9.18, 8.72(m, 8H), 4.60(t, 4H), 4.10, 4.05(s,18H), 2.35(t, 4H), 2.21-1.32(m, 24H)

¹³C NMR spectrum (ppm) 148.17, 145.73, 126.04, 88.14, 68.18, 67.75,66.87, 60.58, 30.52, 28.31, 28.21, 28.05, 27.51, 27.20, 26.94

Synthesis 19

Synthesis of 1,1′-bis(4-ferrocenylbutyl)-4,4′-bipyridiniumbis(tetrafluoroborate)

0.5 g (0.56 mmol) of the bipyridinium salt obtained by Synthesis 16 wasdissolved in 10 ml water, and 2 ml of a saturated aqueous solution ofNaBF₄ were added thereto.

The precipitate was recovered and then recrystallized with water therebyobtaining the intended bipyridinium salt.

Elemental analysis Calculated: C:59.78, H:6.32, N:3.03 Measured:C:59.53, H:6.07, N:2.78

¹H NMR Spectrum 9.28, 8.66(m, 8H), 4.57(t, 4H), 4.10, 4.05(s, 18H),2.40(t, 4H), 2.30-1.28(m, 24H)

¹³C NMR spectrum (ppm) 148.27, 145.68, 125.87, 88.05, 68.20, 67.77,66.88, 60.58, 30.51, 28.30, 28.23, 28.05, 27.49, 27.18, 26.97

EXAMPLE 1

An epoxy sealant was applied in the form of lines along the peripheraledges of a transparent glass substrate coated with ITO, except for aportion to be used for injecting a solution. Over this substrate,another transparent glass substrate coated with ITO was superposed suchthat their ITO surfaces face each other and then the epoxy sealant wascured with pressurizing thereby producing a hallow cell with aninjection port.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of γ-butylolactone, 0.02 g of1-(4isopropylphenyl)-2-hydroxy-2-methylpropae-1-on, and 0.15 g of3-(5-methyl-2H-benzotriazole-2-yl)-5-(1-methylethyl)-4-hydroxybenzenepropanoic acid. To the mixed solution was added lithium tetrafluoroboricacid and a compound represented by the formula below such that theconcentration of each compound is made to 1.0M and 30 mM, respectively,thereby obtaining a homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light thereby obtaining an electrochromic smart window.

The smart window when assembled was not colored and had a transmittancyof about 80%. The smart window was quick in response to the applicationof an electric voltage and exhibited excellent electrochromicproperties. The smart window was colored in blue upon application of avoltage of 1.0 V and had 20% transmittancy of 633 nm wavelength light.Coloring and bleaching operations were repeated every 10 seconds, but noremnant coloration was observed even after the lapse of about 200 hours.

EXAMPLE 2

A mixed solution was prepared by mixing 1.0 g of methoxypolyethyleneglycol monomethacrylate (the number of oxyethylene unit: 4) manufacturedby Shin Nakamura Chemical CO. LTD. under the trade name of M40GN, 0.02 gof polyethylene glycol dimethacrylate (the number of oxyethylene unit:9) manufactured by Shin Nakamura Chemical CO. LTD. under the trade nameof 9G, 4.0 g of propylene carbonate, 0.02 g of1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-on, and 0.15 g of3-(5-methyl-2H-benzotriazole-2-yl)-5-(1-methylethyl)-4-hydroxybenzenepropanoic acid. To the mixed solution was added tetrafluoroboric acidtetrabutylammonium salt and a compound represented by the formula belowsuch that the concentration of each compound is made to 0.1M and 30 mM,respectively, thereby obtaining a homogeneous solution.

The homogeneous solution was deaerated and injected into a cell preparedby the procedures of Example 1 through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light thereby obtaining an electrochromic smart window.

The smart window when assembled was not colored and had a transmittancyof about 80%. The smart window was quick in response to the applicationof an electric voltage and colored in blue-green, i.e., exhibitedexcellent electrochromic properties. The smart window was colored inblue-green upon application of a voltage of 1.0 V and had 25%transmittancy of 633 nm wavelength light. Coloring and bleachingoperations were repeated every 10 seconds, but no remnant coloration wasobserved even after the lapse of about 1,000 hours.

EXAMPLE 3

A smart window was prepared by following the procedures of Example 2except for using a compound represented by the formula below as achromogenic material.

The smart window when assembled was not colored and had a transmittancyof about 76%. The smart window was quick in response to the applicationof an electric voltage and colored in green,i.e., exhibited excellentelectrochromic properties. The smart window was colored in blue-greenupon application of a voltage of 1.0 V and had 22% transmittancy of 633nm wavelength light. Coloring and bleaching operations were repeatedevery 10 seconds, but no remnant coloration was observed even after thelapse of about 1,000 hours.

EXAMPLE 4

An electrochromic mirror was prepared by following the procedures ofExample 2 except for using a compound represented by the formula belowas a chromogenic material and providing a reflective layer on either oneof the ITO-coated substrate.

The mirror when assembled was not colored and had a transmittancy ofabout 70%. The mirror was quick in response to the application of anelectric voltage and colored in green, i.e., exhibited excellentelectrochromic properties. The mirror was colored in blue-green uponapplication of a voltage of 1.0 V and had 8% transmittancy of 633 nmwavelength light. Coloring and bleaching operations were repeated every10 seconds, but no remnant coloration was observed even after the lapseof about 500 hours.

EXAMPLE 5

A smart window was prepared by following the procedures of Example 2except for using a compound represented by the formula below as achromogenic material.

The smart window when assembled was not colored and had a transmittancyof about 80%. The smart window was quick in response to the applicationof an electric voltage and colored in green,i.e., exhibited excellentelectrochromic properties. The smart window was colored in blue-greenupon application of a voltage of 1.0 V and had 20% transmittancy of 633nm wavelength light. Coloring and bleaching operations were repeatedevery 10 seconds, but no remnant coloration was observed even after thelapse of about 1,000 hours.

EXAMPLE 6

An epoxy sealant was applied in the form of lines along the peripheraledges of a transparent glass substrate coated with ITO, except for aportion to be used for injecting a solution. Over this substrate,another transparent glass substrate coated with ITO was superposed suchthat their ITO surfaces face each other and then the epoxy sealant wascured with pressurizing thereby producing a hallow cell with aninjection port.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of propylene carbonate, 0.02 g of1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-on, and 0.15 g of3-(5-methyl-2H-benzotriazole-2-yl)-5-(1-methylethyl)-4-hydroxybenzenepropanoic acid. To the mixed solution was added tetrafluoroboric acidtetrabutylammonium salt and a compound represented by the formula belowsuch that the concentration of each compound is made to 0.1M and 30 mM,respectively, thereby obtaining a homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light thereby obtaining an electrochromic smart window.

The smart window when assembled was not colored and had a transmittancyof about 80%. The smart window was quick in response to the applicationof an electric voltage and colored in blue-green, i.e., exhibitedexcellent electrochromic properties. The smart window was colored inblue-green upon application of a voltage of 1.0 V and had 20%transmittancy of 633 nm wavelength light. Coloring and bleachingoperations were repeated every 10 seconds, but no remnant coloration wasobserved even after the lapse of about 500 hours.

EXAMPLE 7

A smart window was prepared by following the procedures of Example 6except for using a compound represented by the formula below as achromogenic material.

The smart window when assembled was not colored and had a transmittancyof about 75%. The smart window was quick in response to the applicationof an electric voltage and colored in blue-green,i.e., exhibitedexcellent electrochromic properties. The smart window was colored inblue-green upon application of a voltage of 1.0 V and had 25%transmittancy of 633 nm wavelength light. Coloring and bleachingoperations were repeated every 10 seconds, but no remnant coloration wasobserved even after the lapse of about 500 hours.

EXAMPLE 8

A smart window was prepared by following the procedures of Example 6except for using a compound represented by the formula below as achromogenic material.

The smart window when assembled was not colored and had a transmittancyof about 75%. The smart window was quick in response to the applicationof an electric voltage and colored in blue-green,i.e., exhibitedexcellent electrochromic properties. The smart window was colored inblue-green upon application of a voltage of 1.0 V and had 29%transmittancy of 633 nm wavelength light. Coloring and bleachingoperations were repeated every 10 seconds, but no remnant coloration wasobserved even after the lapse of about 200 hours.

EXAMPLE 9

An epoxy sealant was applied in the form of lines along the peripheraledges of a transparent glass substrate coated with ITO, except for aportion to be used for injecting a solution. Over this substrate,another transparent glass substrate coated with ITO was superposed suchthat their ITO surfaces face each other and then the epoxy sealant wascured with pressurizing thereby producing a hallow cell with aninjection port.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of propylene carbonate, 0.02 g of1-(4isopropylphenyl)-2-hydroxy-2-methylpropane-1-on, and 0.15 g of3-(5-methyl-2H-benzotriazole-2-yl)-5-(1-methylethyl)-4-hydroxybenzenepropanoic acid. To the mixed solution was added tetrafluoroboric acidtetrabutylammonium salt and a compound represented by the formula belowsuch that the concentration of each compound is made to 0.1M and 30 mM,respectively, thereby obtaining a homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light thereby obtaining an electrochromic smart window.

The smart window when assembled was not colored and had a transmittancyof about 80%. The smart window was quick in response to the applicationof an electric voltage and colored in blue-green, i.e., exhibitedexcellent electrochromic properties. The smart window was colored inblue-green upon application of a voltage of 1.0 V and had 25%transmittancy of 633 nm wavelength light. Coloring and bleachingoperations were repeated every 10 seconds, but no remnant coloration wasobserved even after the lapse of about 200 hours.

EXAMPLE 10

A smart window was prepared by following the procedures of Example 9except for using a compound represented by the formula below as achromogenic material.

The smart window when assembled was not colored and had a transmittancyof about 75%. The smart window was quick in response to the applicationof an electric voltage and colored in blue-green,i.e., exhibitedexcellent electrochromic properties. The smart window was colored inblue-green upon application of a voltage of 1.0 V and had 25%transmittancy of 633 nm wavelength light. Coloring and bleachingoperations were repeated every 10 seconds, but no remnant coloration wasobserved even after the lapse of about 200 hours.

EXAMPLE 11

A smart window was prepared by following the procedures of Example 9except for using a compound represented by the formula below as achromogenic material.

The smart window when assembled was not colored and had a transmittancyof about 75%. The smart window was quick in response to the applicationof an electric voltage and colored in blue-green,i.e., exhibitedexcellent electrochromic properties. The smart window was colored inblue-green upon application of a voltage of 1.0 V and had 25%transmittancy of 633 nm wavelength light. Coloring and bleachingoperations were repeated every 10 seconds, but no remnant coloration wasobserved even after the lapse of about 200 hours.

EXAMPLE 12

An epoxy sealant was applied in the form of lines along the peripheraledges of a transparent glass substrate coated with ITO, except for aportion to be used for injecting a solution. Over this substrate,another transparent glass substrate coated with ITO was superposed suchthat their ITO surfaces face each other and then the epoxy sealant wascured with pressurizing thereby producing a hallow cell with aninjection port.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of γ-butyrolactone, 0.02 g of1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-on, and 0.15 g of3-(5-methyl-2H-benzotriazole-2-yl)-5-(1-methylethyl)-4-hydroxybenzenepropanoic acid. To the mixed solution was added lithium tetrafluoroboricacid and a compound represented by the formula below such that theconcentration of each compound is made to 1.0M and 15 mM, respectively,thereby obtaining a homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light thereby obtaining an electrochromic smart window.

The smart window when assembled was not colored and had a transmittancyof about 80%. The smart window was quick in response to the applicationof an electric voltage and exhibited excellent electrochromicproperties. The smart window was colored in blue upon application of avoltage of 1.0 V and had 35% transmittancy of 633 nm wavelength light.Coloring and bleaching operations were repeated every 10 seconds, but noremnant coloration was observed even after the lapse of about 200 hours.

EXAMPLE 13

An epoxy sealant was applied in the form of lines along the peripheraledges of a transparent glass substrate coated with ITO, except for aportion to be used for injecting a solution. Over this substrate,another transparent glass substrate with the same size coated with ITOwas slightly shifted and superposed such that their ITO surfaces faceeach other and then the epoxy sealant was cured with pressurizingthereby producing a hallow cell with an injection port.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of γ-butyrolactone, 0.02 g of1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-on, and 0.15 g of3-(5-methyl-2H-benzotriazole-2-yl)-5-(1-methylethyl)-4-hydroxybenzenepropanoic acid. To the mixed solution was added lithium perchlorate anda compound represented by the formula below such that the concentrationof each compound is made to 0.8M and 30 mM, respectively, therebyobtaining a homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light. A belt- or narrow strip-like electrode is soldered onthe shifted portion thereby obtaining an electrochromic smart window.

The smart window when assembled was not colored and had a transmittancyof about 85%. The smart window was quick in response to the applicationof an electric voltage and exhibited excellent electrochromicproperties. The smart window was colored upon application of a voltageof 1.1 V and had 20% transmittancy of 633 nm wavelength light. Coloringand bleaching operations were repeated every 10 seconds, but no remnantcoloration was observed even after the lapse of about 200 hours.

EXAMPLE 14

An epoxy sealant was applied in the form of lines along the peripheraledges of a transparent glass substrate coated with ITO, except for aportion to be used for injecting a solution. Over this substrate,another transparent glass substrate coated with ITO was superposed suchthat their ITO surfaces face each other and then the epoxy sealant wascured with pressurizing thereby producing a hallow cell with aninjection port.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of propylene carbonate, 0.02 g of1-(4-isopropylphenyl)-2-hydroxy-2-mnethylpropane-1-on, and 0.15 g of2-hydroxy-4-methoxybenzophenone. To the mixed solution was added lithiumperchlorate and a compound represented by the formula below such thatthe concentration of each compound is made to 0.8M and 30 mM,respectively, thereby obtaining a homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light thereby obtaining an electrochromic smart window.

The smart window when assembled was not colored and had a transmittancyof about 87%. The smart window was quick in response to the applicationof an electric voltage and exhibited excellent electrochromicproperties. The smart window was colored in blue-green upon applicationof a voltage of 1.1 V and had 25% transmittancy of 633 nm wavelengthlight. Coloring and bleaching operations were repeated every 10 seconds,but no remnant coloration was observed even after the lapse of about 200hours.

EXAMPLE 15

A laminate was prepared by forming a thin film of palladium as a highlyreflective electrode, over a substrate. An epoxy sealant was applied inthe form of lines along the peripheral edges, except for a portion to beused for injecting an electrolyte precursor solution, of the palladiumfilm layer of the laminate. A transparent glass substrate coated withSnO₂ was superposed over the laminate such that the SnO₂ surface and thepalladium film layer face each other and then the epoxy sealant wascured with pressurizing thereby forming a hallow cell with an injectionport.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of propylene carbonate, 0.02 g of2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 0.15 g of3-(2H-benzotriazole-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzeneethanoic acid. To the mixed solution was added lithium perchlorate and acompound represented by the formula below such that the concentration ofeach compound is made to 0.8M and 30 mM, respectively, thereby obtaininga homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light thereby obtaining an electrochromic mirror.

The mirror when assembled was not colored and had a reflectance of about70%. The mirror was quick in response to the application of an electricvoltage and exhibited excellent electrochromic properties. The mirrorwas colored upon application of a voltage of 1.1 V and had a reflectanceof 10%. Coloring and bleaching operations were repeated every 10seconds, but no remnant coloration was observed even after the lapse ofabout 200 hours.

EXAMPLE 16

A laminate was prepared by forming a thin film of palladium as a highlyreflective electrode, over a substrate. An epoxy sealant was applied inthe form of lines along the peripheral edges, except for a portion to beused for injecting an electrolyte precursor solution, of the palladiumfilm layer of the laminate. A transparent glass substrate coated withSnO₂ was slightly shifted and superposed over the laminate such that theSnO₂ surface and the palladium film layer face each other and then theepoxy sealant was cured with pressurizing thereby forming a hallow cellwith an injection port.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of propylene carbonate, 0.02 g of2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 0.15 g of2-hydroxy-4-methoxybenzophenone-5-carboxylic acid. To the mixed solutionwas added tetrafluoroboric acid and a compound represented by theformula below such that the concentration of each compound is made to0.8M and 30 mM, respectively, thereby obtaining a homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light. A belt- or narrow strip-like electrode was solderedon the shifted portion of the SnO₂ surface of the SnO₂-coated substratethereby obtaining an electrochromic mirror.

The mirror when assembled was not colored and had a reflectance of about70%. The mirror was quick in response to the application of an electricvoltage and exhibited excellent electrochromic properties. The mirrorwas colored upon application of a voltage of 1.1 V and had a reflectanceof 10%. Coloring and bleaching operations were repeated every 10seconds, but no remnant coloration was observed even after the lapse ofabout 200 hours.

EXAMPLE 17

A laminate was prepared by forming a thin film of palladium as a highlyreflective electrode, over a substrate. An epoxy sealant was applied inthe form of lines along the peripheral edges, except for a portion toused for injecting an electrolyte precursor solution, of the palladiumfilm layer of the laminate. A transparent glass substrate coated withSnO₂ was superposed over the laminate such that the SnO₂ surface and thepalladium film layer face each other and then the epoxy sealant wascured with pressurizing thereby forming a hallow cell with an injectionport.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of propylene carbonate, 0.02 g2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 0.03 g of2-(5-methyl-2-hydroxyphenyl)benzotriazole manufactured by CIBA-GEIGYunder the tradename of TINUVIN P. To the mixed solution was addedtetrafluoroboric acid trimethylethylammonium and a compound representedby the formula below such that the concentration of each compound ismade to 0.5M and 30 mM, respectively, thereby obtaining a homogeneoussolution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light thereby obtaining an electrochromic mirror.

The mirror when assembled was not colored and had a reflectance of about70%. The mirror was quick in response to the application of an electricvoltage and exhibited excellent electrochromic properties. The mirrorwas colored upon application of a voltage of 1.1 V and had a reflectanceof 10%. Coloring and bleaching operations were repeated every 10seconds, but no remnant coloration was observed even after the lapse ofabout 200 hours.

EXAMPLE 18

An epoxy sealant was applied in the form of lines along the peripheraledges of a transparent glass substrate in a size of 4 cm×4 cm coatedwith ITO, except for a portion to be used for injecting a solution. Overthis substrate, another transparent glass substrate with the same sizecoated with ITO was slightly shifted and superposed such that their ITOsurfaces face each other and then the epoxy sealant was cured withpressurizing thereby producing a hallow cell with an injection port.

On the other hand, a mixed solution was prepared by mixing 1.0 g ofmethoxypolyethylene glycol monomethacrylate (the number of oxyethyleneunit: 4) manufactured by Shin Nakamura Chemical CO. LTD. under the tradename of M40GN, 0.02 g of polyethylene glycol dimethacrylate (the numberof oxyethylene unit: 9) manufactured by Shin Nakamura Chemical CO. LTD.under the trade name of 9G, 4.0 g of γ-butyrolactone, 0.02 g of1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-on, and 0.15 g of3-(5-methyl-2H-benzotriazole-2-yl)-5-(1-methylethyl)-4-hydroxybenzenepropanoic acid. To the mixed solution was added lithium tetrafluoroboricacid and a compound represented by the formula below such that theconcentration of each compound is made to 0.5M and 100 mM, respectively,thereby obtaining a homogeneous solution.

The homogeneous solution was deaerated and then injected into the cellobtained above through the injection port.

After the injection port was sealed with an epoxy sealant, the solutionin the cell was cured by exposing both the surfaces of the cell tofluorescent light. An electrode layer is soldered provided on theshifted portion thereby obtaining an electrochromic smart window.

The smart window when assembled was not colored and had a transmittancyof about 85%. The smart window was quick in response to the applicationof an electric voltage and exhibited excellent electrochromicproperties. The smart window was colored upon application of a voltageof 1.3 V and had about 5% transmittancy of 633 nm wavelength light.Coloring and bleaching operations were repeated every 10 seconds, but noremnant coloration was observed even after the lapse of about 200 hours.

5 in length×3 in width of the devices were arranged so as to be 15 intotal and each was connected to a power source so as to be controlled inOn-Off, thereby obtaining a display panel which can display numbers,(see FIGS. 6 and 7).

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

We claim:
 1. An electrochromic device having an ion conductive layerdisposed between two electrically conductive substrates, at least one ofwhich is transparent, wherein said ion conductive layer contains anorganic compound having per molecule both a structure exhibiting acathodic electrochromic characteristic and a structure exhibiting ananodic electrochromic characteristic, wherein said structure exhibitinga cathodic electrochromic characteristic is a bipyridinium ion-pairstructure represented by formula (1) below, and said structureexhibiting an anodic electrochromic characteristic is a metallocenestructure represented by the formula (2) or (3) below:

wherein A⁻and B⁻are each independently a pair-anion selected from thegroup consisting of a halogen anion, ClO₄ ⁻, BF₄ ⁻, PF₆ ⁻, AsF₆ ⁻, SbF₆⁻, CHCOO⁻, and CH₃(C₆H₄)SO₃ ⁻; and

wherein R¹ and R² are each independently a hydrocarbon group selectedfrom the group consisting of an alkyl, alkenyl and aryl group having 1to 10 carbon atoms, in the case where R¹ or R² is an aryl group, thearyl group optionally forms a condensed ring together with acyclopentadienyl ring, m is an integer of 0≦m≦4, n is an integer of0≦n≦4, and Me represents Cr, Co, Fe, Mg, Ni, Os, Ru, V, X—HF—Y, X—Mo—Y,X—Nb—Y, X—Ti—Y, X—V—Y or X—Zr—Y wherein X and Y are each independentlyselected from the group consisting of hydrogen, halogen, and an alkylgroup having 1 to 12 carbon atoms.